Photo by Rodrigo Rodrigo Rodrigo Rodrigo Rodrigo Rodrigo

It’s amazing to me how easy it is to forget to move.

This year was the first time in about 5 years that I found myself gaining weight. It wasn’t a lot, just 5 lbs over 6 months or so, but it was strange for me since I didn’t think I was doing anything different.

I write and think about healthy living all the time, and I absolutely love the food I eat. I no longer crave sugar, and avoiding it isn’t hard. If anything I have eaten healthier than ever during this time, since I started working at home and control 100% of my meals. I’ve been eating the same or better quality food than I always have, and have even improved on my mindful eating techniques.

So what gives?

I didn’t think the problem was exercise, since I still go to the gym 4-6 days a week. My workouts have actually gotten better, and I’ve noticed welcome improvements in several aspects of my physique (thank you kettlebell!). I wasn’t upset about how I looked, I had just gotten slightly larger and didn’t know why.

Then about 6 weeks ago I figured it out: I had stopped walking.

When I was still in my PhD program I had a substantial walk to work, at least a mile each way if I took the campus shuttle, and about 2.5 miles each way if I walked the whole distance (I did this rarely, but tried to squeeze it in when I could). I also worked in the lab, running back and forth between rooms and up and down stairs to get equipment. Though I came home each evening and worked on Summer Tomato until the wee hours of the morning, I was not sedentary.

Even during my brief stint in the corporate world after graduation I had a walking commute to work. But after I quit in January I just stayed at home writing. At first I had a standing desk/table I was using, but logistics and a problematic elbow forced me to move to the coffee shop across the street where most of my work gets done now. This sedentary shift correlates exactly with when I noticed my pants getting tighter.

What’s crazy to me is that this amount of exercise seems so inconsequential it doesn’t even register in my brain until months after the change has occurred. And it’s not like I never think about this stuff, I noticed when I first started walking that I effortlessly dropped weight. How could I forget that non-exercise activity (NEAT) is so important?

It’s easy to forget, but this is good news. It means that it is not a chore to burn more calories—in fact, you will hardly notice. All you need to do is make an effort to be a little more active throughout the day, and work to build more activity into your daily routine.

To solve my problem, I turned to my puppy Toaster. He needs to get out and walk a few times a day, so I thought why not improve both of our lives by making a daily pilgrimage to the bigger, better park that’s about a mile from the house instead of the smaller, dirtier park that is closer and more convenient? He gets more exercise and behaves better, I get my walk in, and we both have more fun. Win-win.

I’m happy to report that my pants are fitting better again.

If you don’t have a dog, there are plenty of other ways to move more. Avoid elevators and escalators, walk to lunch or between floors in your building, do chores more enthusiastically at home and park further away in the parking lot. Just standing up more can make a difference. These things add minuscule amounts of time to your tasks but add up significantly for your health.

Unlike structured, high-intensity exercise, walking and other low-intensity movements don’t make you hungrier. There’s good evidence that increasing your daily activity can burn hundreds of extra calories each day and may be one of the most effective ways to impact your energy balance (i.e. burn more without eating more). Importantly, non-exercise activity correlates with body weight in obese as well as normal weight individuals, so everyone can benefit from extra movement.

Even if you already work out regularly you should still strive for additional daily activity. Amazingly, high-intensity exercise doesn’t lower your inclination toward NEAT, but raises it. In one study, scientists measured NEAT 3 days before and 3 days after overweight individuals performed either moderate or high-intensity exercise. There was no measurable change in NEAT until the third day after exercise, when it increased 17% after moderate activity and 25% after intense activity. That’s impressive.

When you’re as busy as I am, it’s easy to make excuses about why extra effort is impossible. But adding a little extra movement to your normal, daily activities is far and away the easiest way to lose weight and improve your health, so why not?

I’ve also found a substantial meditative value in incorporating more physical activity. Several of my most complex problems have been solved during my walks and I’ve been plowing through podcasts and audiobooks, which I swear makes me smarter (I’m currently loving The Social Animal, by David Brooks). Your brain truly appreciates a break from the screen.

Ironically, it took noticing that I was “reading” less to make me examine what was different in my life—I realized I was listening to fewer audiobooks because I was walking less, and put 2 and 2 together. Problem solved.

It’s easy to be lazy and just wait for the elevator with everyone else, even though you know the time it saves you is insignificant. But today I hope I’ve convinced you that it’s worth resisting that urge and making an effort to be more active. Try making it a game or competing with your friends using pedometers like the FitBit for extra motivation.

What will it take to get you moving?

Photo by Mr. T in DC

“I’ve always wondered what the scientific perspective of alcohol consumption is. I have been doing some research but the actual effects of it on the body range from beneficial to cancerous.”

The clinical science on alcohol consumption is vast and diverse. It’s easy to find studies that demonstrate the benefits of alcohol, but it is equally common to find research showing its dangers. Sorting through the data is not trivial, and getting the right answer from news reports is virtually impossible.

Let’s start with the facts:

1. Alcohol is addictive

Alcohol addiction is one of the most well-understood and dangerous risks of drinking. A propensity for addiction can run in families, but can affect anyone who drinks in excess. None of the health benefits of alcohol can negate the destruction caused by addiction, and anyone who drinks should be careful to avoid this terrible condition.

2. Alcohol damages the liver

Alcohol metabolism occurs in the liver and can cause severe damage when consumed in large quantities. Liver damage can usually be reversed if alcohol consumption stops.

3. Alcohol is associated with breast cancer (sort of)

Drinking is weakly associated with an increased risk of breast cancer. This is likely because alcohol increases aromatase activity in the human body, which increases estrogen production. Estrogen imbalance is a known cause of breast cancer. However, the association between drinking and breast cancer is negated by sufficient folate intake. Folate or folic acid is a B vitamin found in leafy green vegetables, fruits and legumes (and fortified foods). In other words, a healthy diet protects against alcohol induced breast cancer risk.

4. Alcohol protects against mortality from heart disease

Drinking alcohol reduces your risk of dying from a heart attack by preventing blood clotting. This effect is not limited to red wine, all spirits elicit substantial protection. The association appears to be dose-dependent, meaning that the more you drink the more protection you get. HOWEVER, you start raising your risk for the above mentioned problems with every additional drink per day. For men the ideal dosage is 2 drinks per day, for women it is 1 drink per day.

5. Alcohol raises good HDL cholesterol

Moderate drinking also reduces your risk of getting heart disease in the first place by raising beneficial HDL cholesterol without raising LDL cholesterol. Low HDL is a serious problem in America, and alcohol could be a significant benefit for some people. Here are other ways to raise your HDL cholesterol.

6. Red wine may slow aging

Aging research has been revolutionized by the discovery of a compound in red wine called resveratrol. Resveratrol has been shown to slow aging substantially in several model organisms. Though the effect in humans is still unknown, red wine is associated with many benefits that seem to go above and beyond the benefits of alcohol in general.

7. Red wine may protect against Alzheimer’s disease

Several studies have shown that red wine is associated with a decreased risk for Alzheimer’s Dementia, a devastating neurodegenerative disease that affects 1 in 4 people over the age of 90. The mechanism of action is unclear, but the benefits may be linked to the effect of red wine on fatty acids in the blood (raising the good stuff), or by slowing the aging process itself.

8. Alcohol causes accidents and behavioral problems

Even relatively safe levels of drinking can be deadly when combined with poor decision making. If you do choose to drink alcohol, always be sure that you’re in a safe environment and can get help if you need it. Being safe sometimes, or even usually, is simply not good enough.

There are plenty of good reasons to avoid alcohol if you choose, and many of the benefits can be garnered by simply increasing the amount or intensity of your daily physical activity.

However, the evidence is pretty clear that moderate alcohol consumption (1-2 drinks per day) can improve health and may be an important component of a healthy lifestyle. This is even true for those who pick up the habit later in life.

And last but certainly not least, some of the best times of my life have been over a drink with friends. And I guarantee you most of us aren’t thinking about our heart health while enjoying a great bottle of wine. As long as you consider safety first, never forget that smiling is one of the healthiest things you will ever do.

Here’s a fun question: what’s your favorite drink??

Originally published July 28, 2010.

Photo by Werwin15

The science of aging is among the most dynamic and provocative in modern biology. Over the past two decades we have seen a virtual explosion in research investigating the molecular and behavioral systems that control the aging process. But the more researchers uncover about the science of aging, the more questions emerge.

Dietary restriction has long been considered the most potent regulator of aging. Restricting food intake by any means induces a series of metabolic changes in organisms from yeast to primates that serve to extend life. Studies are currently underway to investigate the ability of dietary restriction to extend life in humans.

Several biological changes are known to occur upon the onset of dietary restriction including a decline in reproductive ability, increased stress resistance and a slowdown of some metabolic processes.

Insulin signaling was among the first molecular pathways to be identified in the regulation of aging, and offered a direct tie between diet and the aging process.  In 1998 UCSF scientist Cynthia Kenyon showed that removing an insulin receptor gene (daf-2) in worms could double their lifespan. Her lab later showed that removing another insulin signaling gene (daf-16) could extend life even longer. I spoke to Kenyon about the relationship between diet and aging for this article.

Blocking insulin signaling in these worms did not just prevent the worms from dying and allow them to age longer. Instead the aging process actually slows so that older worms continue to behave like young worms. Also, as these experiments were repeated in different animals, it was shown that lowering insulin signaling also helps protect animals from stress and diseases such as cancer and heart disease.

Insulin is released as a direct response to glucose in the blood. This means that any time you eat a meal with carbohydrates, you are increasing your insulin signaling and likely accelerating aging. But this does not mean that you will live forever if you stop eating carbohydrates.

Interestingly, protein metabolism also contributes to accelerated aging, but through a different mechanism. Even more intriguing is that restricting protein increases lifespan to a greater extent than restricting sugar.

So is it simply calories that promote aging?

Probably not. For one thing, the effect of a calorie from protein is greater than a calorie from carbohydrate, making it unlikely that a calorie is the basic unit of impact. Second, there is evidence that calories are not required to accelerate aging.

Recent studies have shown that the mere act of smelling food can reduce lifespan. The mechanism for this effect is still unknown, but seems to be tied to respiration.

According to Kenyon it is clear that “sensory perception influences lifespan,” at least in worms and flies.

Thus it is likely that aging is controlled by the interaction of several pathways, including metabolism, respiration and stress. Importantly, however, lifespan seems to be dependent on a handful of specific pathways rather than global changes in cellular function or breakdown. The idea that aging is an inevitable function of time must be put aside given the evidence that it is controlled at a genetic and environmental level.

This makes sense when you think about it. Different organisms exhibit vastly different lifespans and rates of aging that are too great to be explained by some kind of universal cellular breakdown. A more parsimonious hypothesis is that organisms differ in specific genetic factors that, combined with environmental influences, regulate lifespan.

So how should we mortal humans react to these findings?

The genes linking diet and aging are highly conserved through evolution, indicating that there is a great chance human aging is sensitive to diet. Indeed, insulin-related genes have been found to be important in long-lived human populations. This suggests that the pathways discovered in worms and other organisms have similar functions in humans.

What is not clear is how much influence diet has on lifespan and to what extent we are able to manipulate it. It is already known that abnormal insulin activity in humans is linked to higher disease rates, especially “diseases of civilization” such as heart disease, hypertension, type 2 diabetes and cancer. And these diseases are clearly associated with diets rich in processed foods, especially refined carbohydrates.

The effect of protein consumption on lifespan in humans has yet to be investigated. Envisioning an experiment that would test the influence of smelling food on human aging is difficult to even imagine.

Although direct evidence is not available, there is good reason to suspect that a diet with low glycemic load may extend human lifespan. In November 2009, Kenyon’s lab reported that adding glucose to a worm’s normal diet shortens lifespan, but has no effect on the long-lived worms that lack insulin signaling genes daf-2 and daf-16. This discovery prompted Kenyon herself to adopt a low-carbohydrate diet.

Despite this there is still not sufficient evidence to recommend a calorie restricted diet for humans to extend life, largely because optimal nutrition levels for a given individual are unknown. However, most people would benefit vastly by eliminating processed foods and refined carbohydrates from their diets as much as possible.

Focusing on fresh, whole foods, enjoying an occasional glass of wine, avoiding smoking and getting regular exercise can add 14 years to the life of an average person. Maintain a healthy weight as well and your outlook gets even better.

Would you change your diet to be healthier and live longer?

Originally published February 3, 2010.

Photo by helgabj

Now you see me, now you don’t.

Today’s guest blogger Tim Harwood is a UK based optometrist who also writes for TreatmentSaver, a website specialized in cosmetic surgery and laser eye surgery.

Top 5 Foods For Maintaining 20:20 Vision

by Tim Harwood

If you are lucky enough to have perfect vision, don’t assume it will last forever. As we get older the chances of us developing an eye disease increases dramatically–10% of people over the age of 65 have macular degeneration, and that increases to 30% over the next 10 years.

To preserve perfect vision, first you have to cover the basics:

• Get regular eye tests: Have your vision tested at least every 24 months, as early detection increases the likelihood a disease can be treated. Although not all diseases are treatable (e.g. macular degeneration), certain diseases such as glaucoma respond excellently to medication when detected early enough.
• Don’t ignore visual symptoms: Regardless of how recently you have had an eye test, you should never ignore visual symptoms. If you see flashing lights, floating specks or blind spots in your vision these could indicate an eye disease that needs urgent attention.

How can food help me maintain perfect vision?

The macula is in the center of our retina and is responsible for central vision, reading and recognizing faces. As we get older our macula shows signs of wear and tear, a process known as macular degeneration. There is no effective treatment for this age-related degeneration, which is why eating the right foods is extremely important.

Within the macula there are 2 key pigments:

1. Lutein
2. Zeaxanthin

Lutein and zeaxanthin are antioxidants found within the macula. These antioxidants reduce the amount of free radicals formed within our body as a natural consequence of our cells using oxygen (oxidation). These free radicals have degenerative effects on our eyes, which are thought to be the cause of macular degeneration. Lutein and zeaxanthin slow down this process and help preserve the macula.

Ophthalmologists are now recommending that people with early signs of macular degeneration take lutein and zeaxanthin supplements or change their diet accordingly.

What foods are high in lutein and zeaxanthin?

Here are the top 5 foods with the highest concentrations of these beneficial nutrients:

1. Kale
2. Spinach
3. Peas
4. Courgette / zucchini
5. Brussel sprouts

Studies show that 6 mg of lutein and zeaxanthin should be eaten daily as part of your diet to provide the maximum benefit to your macula. This equates to about one large bowl of spinach or kale daily. Even if you can’t eat this amont every day, it is worth the effort to eat as much of these vegetables as you can manage.

Though these nutrients do not guarantee protection against macular degeneration, evidence suggests they at least slow the progression of the disease. In any case these vegetables are extremely healthy and may also protect against other conditions caused by oxidation such as cancer, diabetes and heart disease.

How’s your vision?

Photo by Lord Jim

“What do you think of the Paleo diet which advocates zero grain consumption?”

The Paleolithic diet is one of the most rapidly growing diet trends of the past several years. Followers of the Paleo diet argue that humans have not evolved to eat agriculture-based foods and can only achieve optimal health by consuming a hunter-gatherer style diet. Thus the Paleo diet is completely devoid of grains and legumes, and also shuns dairy, salt, refined sugar and processed oils. The diet is composed primarily of meats, fish, vegetables, fruits, roots, nuts and seeds.

(The Wikipedia article on the Paleo diet is actually pretty good if you’d like to read up on the details. I particularly like the Opposing views section.)

Like most diets the Paleo diet has a little bit of good science behind it, but also a lot of logical leaps and baseless assumptions. The evolutionary argument that humans are somehow maladapted to agriculture-based diets is particularly unconvincing (resting on many unproven assumptions), yet is the fundamental premise on which the Paleo diet bases its recommendations.

The reasoning behind the Paleo diet is less interesting to me, however, than the impact of the diet itself. Will “eating like a caveman” really help you be healthier?

Possibly, but not necessarily.

The most obvious advantage of the Paleo diet is the lack of processed foods. There is ample evidence that societies on traditional diets boast far better health than those on modern, Western diets–and the hallmark of modern diets is food processing. Paleo diets therefore are low in sugar, refined carbohydrates, trans fats, excess salt and pretty much everything else that leads to “diseases of civilization.”

Paleo diets are also abundant in healthy, nutrient-rich foods such as vegetables, fruits, nuts, fish and meats. I have no doubt that anyone willing to stick to a Paleo eating plan will have a healthy weight and remain virtually free of heart disease, diabetes, hypertension and may even have lower rates of cancer.

But the question still remains, is it necessary to eat Paleo to be healthy?

This is where I take issue with the Paleo philosophy. While a diet completely free of processed foods is undeniably healthy, the Paleo diet goes beyond this and demands considerable sacrifice.

Paleo diets do not allow for any grains or legumes. This pretty much eliminates every traditional cuisine on earth including Japanese, Italian, Indian and Greek. Not only is this a culinary tragedy, it ignores the fact that these cuisines feed some of the world’s healthiest and longest-lived individuals.

Traditional, global diets that exclude highly processed foods but also include grains and legumes have been some of the most successful for health. Diseases of civilization are only problematic in Western cultures where processed foods make up a large proportion of the calories and few whole food are consumed.

Proponents of the Paleo diet argue that it is necessary to eliminate grains and legumes because they contain “antinutrients,” substances that can interfere with the body’s absorption of other important vitamins, minerals and proteins. However, well-nourished individuals who eat a varied diet of unprocessed foods (including grains and legumes) are not nutrient deficient and are generally healthy.

Given that it is possible to thrive on a diet that includes some grains, legumes and even small amounts of processed foods, one must question if giving up the culinary joys of travel and global cuisine are really worth the sacrifice.

In my experience, food substitutions and modified recipes designed to mimic traditional meals can sometimes be tasty but can never replace true authenticity.

Another contention I have with the Paleo diet is the assumption that the same eating patterns will work for everyone. People’s lives differ in countless ways. We each have different levels of daily activity, demands on our time and food preferences. We also have different genetic backgrounds, which can result in significant differences in metabolism and hormone levels. These individual variations make dietary needs different for each of us.

Because of our individual differences, there is undoubtedly a percentage of the population that thrives on the Paleo diet and finds it easy to stick to and achieve results. Hooray! However there may also be a segment of the population (myself included) that finds living without grains and legumes to be chronically unsatisfying and unsustainable.

Try telling a foodie they can never eat cheese or drink wine again and see how far you get pitching a Paleo diet.

If you currently eat a typical Western diet with little variety and many processed foods, tend to have better success following rigid diet plans, and have no qualms about giving up or modifying traditional meals to meet your dietary demands, then you might have luck following the Paleo diet. However there is no reason to believe it is the only path to good health.

The best diet is the one that works for you. Finding a healthstyle you can embrace and enjoy is essential if you want to build a lifetime of healthy habits.

Do you follow a Paleo diet? What do you think?

Originally published February 22, 2010.

Photo by Venex_jpb

If there is a single subject that befuddles the health-conscious eater, it is undoubtedly carbohydrates.

Most of us have seen the impressive results of at least temporarily restricting carbs, but studies examining the long-term effects of carbohydrate restriction are often ambiguous. Also, while some experts argue fervently for a low-carb lifestyle, some nutritionists still warn about the dangers of eating too much fat or protein.

So how do we know what to believe?

A full examination of the science behind carbohydrate metabolism is beyond the scope of a single blog post, and is in fact not entirely understood by the scientific community (for a thorough review of this topic read Gary Taubes’ book Good Calories, Bad Calories, which I have reviewed here).

However, there are a few things we do know about carbohydrates that are worth pointing out.

Lesson 1: Refined grains contribute to nearly every chronic disease in modern civilization.

It is universally agreed in the nutrition community that refined, processed carbohydrates are the worst things to eat on the entire planet.

And it is impossible to overstate how remarkable this is.

The nutrition community is one of the most disagreeable bunches in all of science. But across the board–from vegans like Colin Campbell to carnivores like Robert Atkins–not a single one of them considers processed carbs to be nutritionally neutral. They all consider them dangerous.

Without question, refined carbohydrates contribute to poor health.

Lesson 2: Vegetables protect against nearly every chronic disease in modern civilization.

Where things start to get more complicated is with unrefined carbohydrates, and the various iterations of this definition. There is ample evidence that the carbohydrates contained in vegetables are not harmful, and possibly beneficial.

To call these vegetable carbohydrates “fiber” is to oversimplify the science, but suffice to say that vegetables are good for you and contribute to your good health.

This is also generally agreed upon.

Lesson 3: Whole grains are different from intact grains.

Few people will argue against my first two points. But bring up whole grains and you will unleash a fury of controversy. Some people believe whole grains to be the cornerstone of any healthy diet, while others consider them superfluous and possibly detrimental to good health. You can find dozens of PhDs and MDs to back up your claims no matter what camp you align with.

So why is there so much disagreement? What does the science say?

The problem is that nutrition science conducted in free-living humans is virtually impossible to interpret. This is largely because the studies are so difficult to control and people’s behavior and self-reporting are so unreliable. Another problem is that the definition of “whole grains” has been watered down to a point where it is virtually meaningless.

One reason whole grains are hard to identify is because the US Food and Drug Administration (FDA) has created a definition that is friendly to food companies, but not to consumers.

The FDA requirements for a manufacturer to use the term “whole grain” on its label (along with the respective health claims) are as follows:

“Cereal grains that consist of the intact, ground, cracked or flaked caryopsis, whose principal anatomical components – the starchy endosperm, germ and bran – are present in the same relative proportions as they exist in the intact caryopsis - should be considered a whole grain food.” (emphasis added by me)

Get it? To be considered “whole,” grains do not actually have to be intact.

Thus food manufacturers create products using this loose definition to their advantage, demolishing grains as normal, then adding back the required ratios of grain parts (germ and bran) to meet the standard.

This is how products like Froot Loops get spiffy health labels claiming they lower heart disease when any unbiased nutrition scientist would agree that, with 41% sugar by weight, Froot Loops almost certainly contribute to heart disease.

On the other hand, there is compelling data that intact whole grains contribute to better health.

Lesson 4: Eating grains is a personal choice, not a nutritional imperative.

The good news is that it is really easy to tell the difference between fake “whole” grains and intact whole grains. If a food actually looks like a grain (i.e., it retains its original form and bran covering), then it is an intact grain. If it looks like a Cheerio, chip, loaf of bread or pasta with a “whole grain” label, then it is a fake whole grain.

People following a primal or paleo diet will argue that this difference is irrelevant and that all grains (and legumes?!) are unnecessary for good health. Personally I disagree, but remain fairly neutral on the personal choice of removing grains from the diet entirely.

Grains do not appear to be necessary for survival (Inuit tribes survive without them), but optimal nutrition may require slightly more effort than would be necessary following a traditional balanced diet.

This is generally how I feel about all healthy, restrictive regimens such as vegetarian, vegan and raw diets. You can make it work for yourself if you are willing to make sacrifices and put in the effort.

However you should be aware that for many people, myself included, cutting whole grains out of your diet completely is extremely difficult and, if you ask me, unnecessarily painful.

Conclusion

When making food choices about grains, the critical question is not whether or not a food is “whole” grain but whether the grain is intact. For this reason, it matters very little if you substitute “whole grain” products for regular refined products such as pasta.

Examples of intact grains are oats, barley, brown rice, whole wheat, quinoa (sort of) and faro. White rice is not a whole grain, and is closer to a refined grain than a whole grain.

For optimal health, processed and refined grains should be eaten very sparingly. Small amounts such as those eaten in traditional cultures can be part of any healthstyle, but including them is a personal choice that will depend on your own goals and preferences.

The irony is that if you are able to remove processed foods from your diet, the way you eat could probably be described as low-carb. But this label really undermines a healthstyle based on real food.

Though I eat relatively few grains compared to most Americans, I cringe when I see the shining example of low-carb living, The Atkins Diet website, with images of fake pancakes and pasta plastered all over it. If that is what low-carb is, I want nothing to do with it.

Processed food is still processed food, whether the carbohydrates have been synthetically removed or not. Stick to eating real food and you’ll never have to worry about carbs.

Do you count your carbohydrates?

Originally published November 25, 2009.

By regelzamora

Today’s guest post is by Travis Saunders, MSc, Certified Exercise Physiologist. Travis and his colleague Peter Janiszewski, Ph.D, MSc, are both PhD trained scientists who have a fantastic blog over at PLoS Blogs, Obesity Panacea.

While Summer Tomato is more food-centric, Obesity Panacea focuses on exercise and physiology.  Perfect match, right?

I asked Travis if he would be kind enough to write a post on how to get more exercise without having to actually go to the gym (NEAT), something both busy and lazy people alike can appreciate.

Personally I’m a big believer in NEAT. A year and a half ago I stopped taking BART to work and started walking instead. To my surprise this added only 5 minutes to my commute time and is infinitely more enjoyable.

Even though I already logged 4-6 regular cardio and strength training workouts per week, this added mileage caused me to drop another 3-5 lbs that has never come back. It also gives me time to listen to my favorite podcasts!

But what is NEAT exactly? For that I’ll turn the mic over to Travis.

Non-Exercise Activity Thermogenesis – It’s NEAT!

by Travis Saunders

For decades, we have been told of the benefits of physical activity, and with good reason – regardless of body weight, people who exercise live longer, healthier lives than people who don’t exercise.

In the past, the focus has been on performing structured sessions of moderate or vigorous exercise (e.g. 30-60 minutes of aerobic exercise on a bike or treadmill).

While intense physical activity has a tremendous health impact, a growing body of evidence suggests that accumulating short bouts of low-intensity physical activity throughout the day can also have substantial health benefits, which may even rival those associated with more vigorous sessions.  This low-intensity physical activity is known as non-exercise activity thermogenesis, or NEAT.

The concept of NEAT was proposed by Dr James Levine, who defines it as:

“…the energy expenditure of all physical activities other than volitional sporting-like exercise. NEAT includes all those activities that render us vibrant, unique and independent beings such as dancing, going to work or school, shoveling snow, playing the guitar, swimming or walking in the modern Mall.”

I can understand why some people would be skeptical that activities like gardening or mall walking could have a measurable impact on health.  After all, those things aren’t exercise, right?

Fortunately, it turns out that the body doesn’t care whether those activities are exercise.  James Levine’s work has shown that NEAT burns an average of 330 calories per day in healthy individuals (and up to nearly 700 calories/day in some people!), and that obese individuals perform drastically less NEAT than their lean counterparts.

Levine has also made convincing arguments that NEAT could burn up to 1000 calories per day when properly incorporated throughout the work day.  These results suggest that NEAT can burn a tremendous amount of calories, which has obvious implications for weight maintenance and obesity prevention.

But the other key benefit to increased NEAT is that it reduces sedentary time, itself a strong predictor of both death and disease.

Independent of total physical activity levels and other risk factors like abdominal obesity, recent evidence suggests that time spent being sedentary (e.g. sitting or lying down) is a strong predictor of metabolic risk, as well as mortality.  This means that regardless of how much they exercise, people who spend more time sitting are at a higher risk than those who sit less.

New research has even shown that merely taking more frequent breaks from sedentary activities (e.g. standing up) is also associated with reduced metabolic risk and abdominal fat levels.  The reasons for these associations are still being worked out (it probably is to due to changes in LPL and glucose transporter protein activity in skeletal muscle, which are altered by even short bouts of inactivity), but the findings are consistent and have been observed in both adults and children.  Since NEAT includes activities like standing and walking, any increases in NEAT will obviously result in reductions in time spent in sedentary activities.

So, how can you reduce your time spent being sedentary and increase your NEAT levels?  Luckily, it’s not very hard.

Here is a brief list, and for more suggestions, please read “10 Ways to Become More Active”, which can be found on Obesity Panacea.

6 Ways To Get More NEAT

1. Buy a Pedometer

Pedometers are beeper-sized devices which are worn on the waist and keep track of the number of steps taken each day.  They are cheap (a good one costs about $20), and are a great way to assess your level of NEAT.  Each week, try to increase your daily step count by 1,000 steps/day, with a goal of reaching at least 10,000 steps per day.  Friendly step-count competitions with co-workers can also be surprisingly fun, and are a great way to promote increased physical activity within the office environment.

2. Take the Stairs

This one is obvious.  I can’t tell you how often I see people taking the elevator up or down one single floor.  It doesn’t save any time, and it deprives people of physical activity.  You don’t have to walk up twenty flights of stairs to make this worthwhile – try to walk up at least one flight, and down at least two, and build up to more flights as you feel up to it.  If you have to go further than you can walk comfortably, take the elevator the rest of the way.

3. Active Transportation

Walk or bike to work and when performing errands whenever possible.  If that is not an option, consider taking public transportation, which almost always involves a short walk at both ends of the trip.  And if you absolutely have to drive, park as far from the door as possible.  It might only add 5 minutes of walking to your day, but that’s 5 minutes you wouldn’t get otherwise.

4. Drink Plenty of Water

This sounds odd, but it’s a trick that I’ve been using for years. If you are constantly sipping water throughout the day, you are going to have to pee at least once every couple hours. Every time you have to pee, you have a guilt-free excuse to go for a 5-minute walk to the washroom and back! To crank it up a notch, use a washroom in another part of your building, which may give you an opportunity to use the stairs as well.  It’s easy to forget to take a 5-minute walk-break every hour, but it’s impossible to forget to go pee.

5. Have “Walk” Meetings

These types of meeting are becoming increasingly popular at my workplace.  Think of all the times that you need to have a 5-10 minute chat with another co-worker or superior.  Instead of doing it at your desk (and potentially annoying your colleagues), why not talk while casually strolling down the hall?  This is another great way to accumulate activity without even noticing that it’s happening.

6. Walk During Your Lunch Break

If you are one of those lucky individuals who has a daily lunch break, why not use it for a short walk?  A ten or twenty minute walk on a daily basis can add up over time, and you’ll almost certainly feel better than if you spent your whole break sitting at your desk.

These are only a few examples, but I hope they illustrate how easy it can be to incorporate more NEAT into your daily life.  Give it a shot, and good luck with your healthstyle!

Let’s have a big round of applause for Travis!

Originally published at Summer Tomato on October 19, 2009

Garlic

People often say that garlic has medicinal properties. Some claim it lowers blood pressure, others swear it helps cholesterol and reduces clotting, and some even think it protects against cancer. I’ve also heard that garlic is “healthier” 10-15 minutes after it has been crushed or minced. Is any of this true?

The Science of Single Foods

As someone who regularly reads the scientific literature on the health benefits of food I can assure you that this is not an easy question to answer. The problem is that the effect of any single food on human health is likely to be small at best, and small effects are very difficult to detect with reliability. Studies must be incredibly well-designed to contribute anything of value to our understanding of how a food works in the human body. Also, many studies must be taken together in context for the data to be evaluated properly.

I have been researching this garlic question on and off for months and feel only slightly more confident today than I did when I started. To summarize, there are a good number of studies addressing the health value of garlic, but very very few of them are well-designed and published in reputable journals. The problem with having a large number of poor-quality studies is that results are often conflicting and difficult to interpret. Thus, when another scientist comes in to do a meta-analysis (pooling data from many studies and re-analyzing it for stronger statistics) the findings are usually inconclusive.

However, inconclusive findings do not enable me (or anyone) to say there is no benefit. What I can say is that more research is needed and if there is a benefit it is likely to be small. (How unsatisfying is that?!). But personally I would still recommend eating garlic for health. Why?

Small Benefits Are Important

Although we cannot say exactly why garlic is good for you, it is almost certainly not bad for you. Moreover, although it is difficult to attribute a particular health benefit to a single food, we do know that people who eat the most vegetables tend to be healthier than people who fewer.

Many nutrition scientists are beginning to suspect that the benefit of foods like garlic are primarily relevant in the context of a whole diet and cannot be evaluated independently. This means that it is less important that the individual studies I mentioned earlier are inconclusive, because they are likely not sensitive enough to evaluate the complex interactions of whole foods and food combinations on human physiology.

The Best Reason To Eat Garlic

The most important thing you can do for your health is eat a diverse diet of natural, unprocessed foods. Garlic is an amazing ingredient that imparts a unique and wonderful taste to the food it is cooked with. If you like garlic and it encourages you to eat your vegetables, then it’s good for you.

If it makes you feel slightly better knowing that it may help your heart or reduce inflammation, that’s awesome but less important.

What About The Crush?

If you do hope garlic can add to your health, is there any benefit in crushing it early? Probably.

Scientists have long suspected that the active ingredient in garlic is a substance called allicin. A recent study from Queen’s University showed that it is actually a decomposition product of allicin that has the most potent antioxidant activity.

Interestingly, allicin is created from an enzyme called alliinase that is not released from plant cells until they are damaged. Alliinase is what gives garlic (and onions) their strong odor and is thought to be a self-defense mechanism for these plants. When garlic is crushed, alliinase becomes active and begins creating allicin. As allicin is created and breaks down, the antioxidant potential of garlic is dramatically increased. Optimal antioxidant levels are created about 10 minutes after garlic is crushed.

It has not yet been shown that this increased antioxidant activity is a benefit to humans, but the principle is compelling enough to try to remember to crush your garlic a little early. If you are anything like me though, this feat is almost impossible. Apparently garlic hasn’t done that much for my memory.

What are your favorite reasons to eat garlic?

Originally published March 27, 2009.

Enough people have asked me if the kind of cholesterol in egg yolks is good or bad (hint: it’s neither) that I think it is time for a brief tutorial on this misunderstood molecule.

Rather than put you to sleep with a watered down version of a Wikipedia article I decided to explain the interaction of diet and cholesterol in a short video. Hopefully this will help clear up what cholesterol is and how you should eat to minimize your risk of heart disease.

As always, feel free to drop me questions in the comments.

If you like this story follow me on the new Digg!

Further reading:

• How To Raise Your HDL Cholesterol
• Intact Grains vs Whole Grains
• How To Make Eggs Taste As Good As Bacon
• Book Review: Good Calories, Bad Calories

Many studies have been published associating lack of sleep with increased body weight, but I have never read through the literature myself to explore the connection.

This week fellow scientist Matthew Constantin of Best Weight Loss Triumph gives us a thorough review of the science of sleep and weight gain.

Matthew Constantin, PhD, is a biologist and postdoctoral research scientist at Saint Louis University. Twice awarded research grants from the American Heart Association for his studies on cardiovascular disease, Matthew also has a keen interest in the related field of obesity treatment and enjoys explaining the latest scientific research on weight loss in a way that is easy for everyone to understand.

His website contains reviews of some of the so-called best rated weight loss programs and offers a savings coupon for Medifast, a clinically studied weight loss intervention.

Obesity and Reduced Sleep: Will Sleeping Less Make Me Fat?

By Matthew Constantin, PhD

We have long known that too little sleep causes fatigue and a slowing of neurocognitive functions, resulting in a variety of symptoms like slowed reaction time and difficulty concentrating. Recent research, however, has discovered a new result of reduced sleep: metabolic effects that include an increased risk of obesity [1].

Western society has seen a rapid rise in overweight and obesity in recent decades. Accompanying this widespread weight gain has been a significant and rapid decrease in the amount of time the average person spends sleeping.

While young adults were sleeping close to 9 hours each night at the beginning of the 20th century [2], this had decreased to less than 8 hours by the late 1960s [3]. The trend is continuing into the 21st century. As of 2005, 16% of American adults were getting less than 6 hours of sleep at night, up from 12% in 1998.

Sleep and Obesity: A Subjective Study

Science has linked self-reported sleep habits and obesity for a number of years, but the precise relationship between the two has been difficult to establish. Because obesity is a risk factor for a number of diseases that can negatively impact sleep, such as sleep apnea, asthma, depression, and arthritis, it is hard to know whether reduced sleep leads to obesity or obesity leads to reduced sleep.

To shed some light on this question, data collected from 1986 to 2002 in the Nurses’ Health Study (NHS) was analyzed [4]. Women in this study were asked to report their sleep habits and body weight every two years.

The results of the study suggest that women who self-report receiving less sleep are more likely to gain weight and are at an increased risk for obesity in middle-age. In 1986, when the first round of data was collected, it was found that women who reported sleeping 7 hours in a 24 hour period weighed 2.6 kg less than those who slept 5 or fewer hours, and 1.3 kg less than those who slept 6 hours.

This pattern continued over the following 16 years, with women who reported getting 5 or fewer hours of sleep weighing the most every time weight data was collected and those getting 7-8 hours of sleep weighing the least. In 2002, those in the 6-hour group had gained 7.2kg (15.8lb) and those in the 5-hour or less group gained 9kg (19.8lb), while those in the 7-hour group had gained only 4.8 (10.6lb) kg.

Other prospective studies have found similar results among both adults and children, but there are a couple of caveats. Because the information in the studies is self-reported, it is subject to inaccurate estimates by the reports. Many people overestimate sleep time when self-reporting. It is also unknown whether shorter sleepers are heavier because of an increase in fat or an increase in lean muscle—a distinction which makes a significant difference for health repercussions.

Sleep and Obesity: An Objective Study

In response to the limitations of subjective studies on sleep and obesity, two groups of adults aged 65+ (one of men and one of women) took part in an objective study that also looked at sleep duration and weight. Rather than relying on self-reported data, participants’ sleep patterns were assessed through the use of wrist actigraphy, which determines if a person is asleep or awake by measuring wrist movement.

This objective measurement of sleep duration confirmed the results of the subjective study, finding that reduced sleep was associated with an increased Body Mass Index (BMI) among both men and women. When compared with those getting 7-8 hours of sleep per night, average BMI of those who slept less than 5 hours was higher by 2.5 units in men and by 1.8 units in women. Moreover, men getting 5 or fewer hours of sleep were 3.7 times more likely to be obese, while women were 2.3 time more likely.

Increased weight doesn’t necessarily mean an increase in fat and its related health problems—more muscle also means more weight, but is generally associated with improved health. The objective study looked at this question and found that the increase in weight associated with reduced sleep was a result of increased fat rather than muscle. Overall percent body fat in those sleeping less than 5 hours was 1.7% greater than those getting 7-8 hours, and percent body fat in the trunk 1.9% greater.

Why Could Reduced Sleep Make You Fat?

Research has clearly shown that reduced sleep is associated with greater weight, but why does reduced sleep make a person fat?

One strong hypothesis is that less sleep leads to increased or altered food intake. Animals studies have found that sleep deprivation leads to elevated levels of hunger [5], with particular increases for high-fat and high-carbohydrate foods. This increased hunger with sleep deprivation may be a result of the corresponding change in hormones that regulate hunger, with gherlin levels found to increase and leptin levels to decrease.

Alternatively, rather than a change in feelings of hunger, increased food intake could be the result of increased eating even in the absence of hunger. Reduced impulse control and trouble delaying gratification are known consequences of sleep deprivation.

It’s also possible that simply being awake more often will lead to increased eating when food is readily available, especially if time awake is spent in sedentary activities that encourage snacking.

As S.R. Patel mentions in his 2009 review paper titled “Reduced sleep as an obesity risk factor”, there are several other possibilities that have been proposed. One is that the feelings of fatigue that are associated with sleep deprivation may result in a disinclination to exercise. Another is that reduced sleep results in a reduction in involuntary activities such as fidgeting, which are known to have effects on weight regulation [6].

Finally, acute sleep deprivation has been found to result in a drop in core body temperature, meaning your body needs to spend less energy in order to maintain thermoregulation with the surrounding air. This change in thermogenesis (the process of heat production) may encourage the storing of fat, although a recent study found no effect of sleep deprivation on resting metabolic rate.

Conclusions

Current evidence clearly shows that short sleep is associated with obesity, but a causal relationship remains unclear. Does a reduction in sleep lead to weight gain, or is there some other reason for the association? We don’t yet know for sure. But as modern society sets aside less and less time for sleep and becomes increasingly prone to obesity, it is a possibility that must be considered.

With so few effective ways to prevent and treat obesity, wouldn’t it be wonderful if simply sleeping a bit more could keep us both thinner and healthier?

References

1. Patel, S.R. Short sleep and obesity. International Association for the Study of Obesity. Obesity Reviews 10 (Suppl. 2), 61–68.

2. Terman L, Hocking A. The sleep of school children, its distribution according to age, and its relationship to physical and mental efficiency. J Educ Psychol 1913; 4: 269–282.

3. Tune GS. Sleep and wakefulness in normal human adults. Br Med J 1968; 2: 269–271.

4. Patel SR, Malhotra A, White DP, Gottlieb DJ, Hu FB. Association between reduced sleep and weight gain in women. Am J Epidemiol 2006; 164: 947–954.

5. Spiegel K, Tasali E, Penev P, Van Cauter E. Sleep curtailment in healthy young men is associated with decreased leptin levels, elevated ghrelin levels, and increased hunger and appetite. Ann Intern Med 2004; 141: 846–850.

6. Levine JA, Eberhardt NL, Jensen MD. Role of nonexercise activity thermogenesis in resistance to fat gain in humans. Science 1999; 283: 212–214.
Matthew Constantin