For The Love Of Food

by | May 11, 2012

For The Love of Food

Welcome to Friday’s For The Love of Food, Summer Tomato’s weekly link roundup.

A scary new link between BPA and breast cancer, a fascinating new discovery about HDL and how one simple habit can help you live 6 extra years.

Want to see all my favorite links? Be sure to follow me on on Delicious. I also share links on Twitter @summertomatoGoogle+ and the Summer Tomato Facebook page. I’m very active on all these sites and would love to connect with you.

Links of the week

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For The Love Of Food

by | Sep 10, 2010

For The Love of Food

Welcome to Friday’s For The Love of Food, Summer Tomato’s weekly link roundup.

The biggest news this week is that I defended my thesis on Tuesday and am now officially a PhD, but that didn’t stop the universe from producing a bunch of other important food and health stories. It might be time for a reality check on your pants size, as well as your understanding of fat and metabolic health. I also found a simple and delicious guide to cooking okra.

I read many more wonderful articles than I post here each week. If you’d like to see more or just don’t want to wait until Friday, be sure to follow me on Twitter (@summertomato) or the Summer Tomato Facebook fan page. For a complete reading list join me on Digg. I’m very active on all these sites and would love to connect with you.

Links of the week

What inspired you this week?

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For The Love Of Food

by | May 7, 2010

For The Love of Food

Welcome to Friday’s For The Love of Food, Summer Tomato’s weekly link roundup.

This week I learned that sugar has yet another dirty trick up its sleeve, E. coli can as easily be in industrial lettuce as in industrial meat (ok, I already knew that) and calorie restriction may strengthen your immune system. I also found a handy short video of Dr. Weil explaining the benefits of the 2010 Dirty Dozen produce list.

I read many more wonderful articles than I post here each week. If you’d like to see more or just don’t want to wait until Friday, be sure to follow me on Twitter (@summertomato) or the Summer Tomato Facebook fan page. For complete reading lists join me on the social bookmarking sites StumbleUpon and Delicious. I’m very active on all these sites and would love to connect with you there. (Note: If you want a follow back on Twitter introduce yourself with an @ message).

Links of the week


What did you learn about food and health this week?

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Body Fat Is Healthy Now? Fat Chance

by | Jun 29, 2009
1 lb Fat

1 lb Fat

Last week the New York Times and many other reputable news sources reported on a Canadian study that claims people with a normal body mass index (BMI) had a slightly increased risk of dying over a 12-year period than those with a BMI in the overweight range (25-29).

The use of the phrase “overweight was protective” landed this article just a hair’s width from being labeled Summer Tomato’s B.S. of the week on Friday. An observational study cannot determine cause and effect, as implied by the word “protective.” This study does not prove that extra body weight protects against all cause mortality, and saying so is irresponsible.

Studies (and reporting) like this have instigated wide-spread confusion about health and body weight. First people are told they are too heavy and should lose weight for health, then in the same breath they are told a little extra weight might not be so bad.

What is the average person supposed to believe? How should we act?

If you want to understand the facts it important to know exactly what the data does and does not say. Indeed, some studies (including one on Japanese men reported in the same issue of Obesity) have reported lower or equal risk of mortality for people with an overweight BMI compared to people of normal BMI (18.5-24). However, this is not the whole story.

First, the alleged benefit of being overweight has only been found in older individuals and does not apply to healthy, young people. Second, although it appears in some cases that overall mortality may be reduced, disease incidence is notably higher in overweight individuals compared to people of normal weight.

bmi-and-chd

To point, a study in the most recent issue of Obesity (same journal, 2 weeks later) examines the relationship of BMI with many measures of cardiovascular disease in healthy, athletic men. In this study, those on the lowest end of BMI in the normal range (18.5-22.5) had a much lower risk of dying from or developing cardiovascular disease than normal weight men with a slightly higher BMI (22.5-25).

Men with the lowest healthy BMIs also had lower risk of hypertension, lower cholesterol and half the risk of diabetes. While the length of this study was only 7.7 years (compared to the 12 years reported in the Times story), there were more than double the number of participants (28,776 vs. 11,834).

(Why did this story not make the news? My guess is that it makes for a less compelling storyline and people would rather not hear it.)

Mortality is certainly an important measure in any study, but it is arguably not the most relevant endpoint. Disease and excess body weight can severely impact quality of life, particularly for older individuals (as illustrated by another study in the latest issue of Obesity). While I cannot speak for everyone, it seems probable that quality of life is equally if not more important than longevity alone. Thus it is questionable how much stock to put into studies that ignore these other factors.

It is also critical to remember that BMI is a measure that was designed to describe people at a population level, not as individuals. While large cohort studies can tell us useful things about relative risk, they are not directly applicable to individual people.

The inconsistency of the data related to BMI and mortality may in fact be an indication of its inadequacy as a general measurement. Remember that BMI represents a ratio between height and weight, making it possible to compare people of various body sizes. Normalizing for height may, however, be deceptive.

Decades of data on caloric restriction consistently show that smaller body size (irrespective of body fat levels and, possibly, BMI) is associated with longer life and decreased risk of nearly all diseases. This is true in all animals from yeast, to worms and flies, to mice and monkeys. While humans are certainly different from all these model organisms, there is tremendous evolutionary precedent indicating smaller body size as the best for health.

The principle of parsimony tells us the simplest hypothesis–that smaller body size is beneficial–is probably correct. Substantial evidence must be accumulated before this hypothesis can be rejected, and I have yet to see that data.

Furthermore, while the research on the risk of overweight may be slightly ambiguous, the data on obesity is not. It is painfully clear that the dangers of obesity are profound and on par with those of smoking cigarettes. Overweight is a necessary step to becoming obese, and according to the National Population Health Survey nearly a quarter of Canadians who were overweight in 1994/1995 were obese by 2002/2003. Since overweight is still a substantial risk factor for becoming obese, misleading public health messages about the benefits of body fat are especially dangerous.

As a consumer of information, the most important thing you can do is be skeptical of what you read. Just because something is printed in the New York Times does not make it true. In fact, many of our most trusted sources of health information do not base their recommendations on rigorous scientific thinking, which is probably the reason for the health disaster we are currently facing.

Thanks to Jan from Quest for Health for sparking this discussion.

What does your gut tell you about the relationship between health and body fat?

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Body Fat Test: One Year Later (part 2)

by | Feb 4, 2009

Last week I had my body fat measured by the gold standard of body composition testing: the hydrostatic body fat test.

I did this test exactly one year ago so I thought it would be informative to see the results a year later (I just checked my email and realized I received my results on January 29, two years in a row). I expected the test to be particularly illuminating this year because of the notable weight loss I have experienced in the past 12 months.

(note: This is part 2 of a 2 part post. Part 1 focuses on the testing experience and what to expect if you go in for a hydrostatic body fat measurement. Part 2 examines my personal body composition changes over the past year. For reference, the picture above shows the volume of 1 lb of fat next to a shallow, superficial coffee mug from Southern California).

I want to begin by saying that last year my body fat percentage was very low for a female, even lower than some athletic males. I am small, eat healthy and am very active so everyone expected I would test at the low end, but my body fat was even lower than any of us imagined.

At the time I did not have a body fat goal, but was very curious about my body composition given my lifestyle.

This year (again) my health goal was not directly related to body fat percentage (I will admit that I would have been disappointed had it gone up), but I have many habits–both new and ongoing–that have the potential to significantly impact my weight, appearance and body composition.

So what did I change and how did it affect me?

Let’s start with my favorite subject: food.

It has been over three years now since I have abandoned dieting and focused on healthy eating. This transition was difficult for me, because I had been on a diet for virtually my entire life (since age 11).

The most notable dietary changes I made were:

  1. Greatly increasing the diversity and quantity of vegetables I eat daily.
  2. Eliminating all nutrition bars, shakes and processed foods.
  3. Greatly increasing plant oils and reducing animal fat.
  4. Increasing plant protein and reducing animal protein.
  5. Increasing whole grains.

Eating more (any) whole grains was by the far the most difficult hurdle for me to overcome. Back in 2003, I would have rather starved than eat any “carbs.”

I have lost weight every year since I changed my diet. This year I dropped (significantly) below my goal weight. And remember, this is after I stopped dieting.

But just because I no longer live on a diet does not mean that I stopped thinking and learning about food. I am constantly reading primary scientific literature and improving my knowledge of nutrition science, and it is impossible for this not to impact the way I choose to eat.

As part of my continuing education, I have further modified my diet over the past 12 months. I have completely stopped buying processed “whole grain” products like Oroweat breads and phony whole grain cereals.

From what I have learned, something is not really “whole grain” unless it actually looks like a grain, no matter what the FDA says. That is to say, the benefits scientists have discovered from whole grain foods are much more substantial if the grains are still intact rather than processed and reconstituted.

Consequently, this year I have a more diverse diet of whole grains, but still occasionally consume processed starches if I find the situation warrants an exception.

Also this year I have made a concerted effort to eat more beans and other legumes for protein. Subsequently I eat fewer animal products and do not consume dairy as part of my daily routine. Don’t get me wrong, I love cheese and creamy sauces. I eat them, but try to limit them to special occasions (like Valentine’s Day).

I have also increased my farmers market shopping from about 50% of my vegetable and fruit purchases to over 90% (I used to regularly supplement my purchases with veggies from Whole Foods and my local market) . This shift was motivated primarily by taste, health and science (local organic foods are more flavorful, more nutritious and have fewer harmful chemicals), but was also influenced by economics and politics.

Another change for me this year was my workout routine.

I used to run marathons and always believed with absolute certainty that cardiovascular workouts were the only way to lose weight. Strength training (weight lifting) was for building up muscle, I thought. I am naturally a muscular, athletic girl and always believed I had plenty of muscle and could live without any extra.

Prior to 2008 I did minimal upper body weight training at the gym, mainly assisted pull ups and dips. But I spent hours on treadmills and elliptical machines.

This year I have been too busy to spend 7+ hours a week doing cardio. I have consequently reduced my cardio workouts to 30 min per day, 5 days a week (or less). I partially make up the difference by walking to my shuttle stop for work (about a mile each way), rather than taking public transportation.

In addition to less intense cardio activity, last summer I began a serious upper body weight lifting regimen. I spend significant time in the weight room using free weight for shoulders, arms, back and abs. I am much stronger in almost every way (except cardio endurance) than I was a year ago.

Interestingly, despite the weight loss and increased strength training, my body fat percentage is exactly the same compared to a year ago (actually 0.1% less, statistically insignificant). That means while I lost some fat, I lost a similar proportion of muscle.**

It is impossible to say why the number is exactly the same, but it is an interesting thing to think about. As I mentioned earlier my upper body is noticeably stronger than it was last year, so it can only be assumed that I increased lean body mass on my upper body. However, my arms are still really small, so this probably represents a tiny percentage of my total weight.

Conversely, my legs (and, um, rear) are substantially smaller (about a size and a half at my favorite denim retailer), so based on my results I would assume that I have lost muscle in my legs because of the drop in strength-building (resistance) cardio work. The added walking does contribute to my cardiovascular fitness, but probably does not add new muscle.

Therefore my hypothesis is that my muscle mass was somewhat redistributed and my total body fat was reduced. Because I only shrunk in mass (not height) the result is a much leaner appearance overall, even though my fat percentage did not change. Although I was happy with my physique last year, deep down I would have admitted that this muscular redistribution was a goal of mine, so I am very happy with the results.

The moral of the story

If you think you need to diet, stop dieting. If you want to lose weight without gaining too much muscle, do less intense cardio workouts and increase strength training.

Five years ago I would have called you crazy if you told me these things, but seeing is believing.

My goal now is to maintain my weight and body fat, and keep focusing on my healthy diet to fight the diseases of affluence (aka diet): heart disease, diabetes, hypertension, cancer and dementia. I hope you join me.

What do you think about my fat and weight loss story?

Click here to read Body Fat Test: One Year Later (part 1)

———-

**I debated for hours whether or not to post my weight and body fat percentage on the internet. I decided not to for the same reason I didn’t post it last year. However, I realize that some of you are info junkies (like me) that would really love a solid number to wrap your brains around. As a compromise, I will send an email with both my weight and body fat as recorded by Fitness Wave (2008 and 2009) to anyone who makes a Paypal donation of $5 or greater to Summer Tomato. The information will be sent to the email address used for the donation unless an alternate address is given. If you have any additional questions or concerns, please email questions@summertomato.com.

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Body Fat Test: One Year Later (part 1)

by | Jan 30, 2009

This week my awesome gym (Bakar Fitness) was once again offering hydrostatic body fat testing courtesy of Fitness Wave.

I had my body fat and metabolic rate tested last year and thought it would be interesting and informative to go in for a one year follow up.

I also want to give you an idea of what to expect if you decide to “get dunked.”

(note: This is part 1 of a 2 part post. The first post focuses on the hydrostatic testing experience rather than my personal story. Come back next week for part 2).

“Hydrostatic” body fat testing is a lot like it sounds: you get weighed under water. The principle behind the method is that virtually all tissues in your body–bones, muscles, organs–weigh more than water. That is, everything sinks except fat. The density of fat is lower than other tissues and consequently, fat weighs less.

Using this knowledge you can calculate how much fat you have by comparing your weight inside and out of the water. The lighter you weigh under water compared to on land, the more fat you have. You can convert this into an exact body fat percentage by doing a little math. (Don’t worry, Fitness Wave does this all for you).

Calculations are even more accurate when you throw in measurements like height. For this test I even had my ankle size measured.

During the test you step into a tank of warm water (pictured to the right) and position yourself on a metal scale. You are instructed to blow out all the air from your lungs and submerge your head while the operator checks your weight. This process is repeated at least three times, and takes about five minutes.

The bottom line is that when packing your bag for your body fat test remember that you will get wet.

A bathing suit and towel are appropriate.

If it is January (or summer in San Francisco), you may also want to bring a change of warm clothes and sandals. When testing, the Fitness Wave trailer is stationed down near the loading docks between the Community Center and Genentech Hall at UCSF Mission Bay. You probably don’t want to walk from the locker room to the trailer in your bikini.

Hydrostatic Testing Checklist:

  1. Bathing suit
  2. Towel
  3. Warm clothes
  4. Convenient shoes
  5. Healthy dose of perspective

Packing your bag is not all the planning you need to do before getting a body fat test. As I explained last year, I also recommend you decide before you go about what you will do with this personal information. Determine beforehand whether or not you want to tell your friends what you are made of to save yourself from stress and awkward conversations later on.

Overall the testing was (once again) a great experience, and I highly recommend getting a hydrostatic test if you get the opportunity. I received a print out of my numbers and an email with more information the next day.

Next time I will reflect upon how my eating and workout habits have affected my body composition over the last year. Check back next week for all the gossip.

Keep up with Summer Tomato by using these links to receive posts via email or RSS feed. Email subscriptions require an activation step once you receive a confirmation in your inbox.

Click here to read Body Fat Test: One Year Later (part 2)

Have you ever had your body fat tested? Are you interested?

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The Latest on Carbs, Fat and Weight Loss

by | Jan 29, 2009

A study published last week in the journal Obesity may make you question whether you really want to rely on the Atkins or South Beach diets to reach your New Year’s Resolution goals.

It is widely believed that low-carbohydrate, high-fat diets support weight loss in most individuals and indeed, there is a good amount of research to back this claim. Despite this, few studies have examined the after effects of a low-carb diet, particularly once normal eating is resumed.

In a new study, scientists had rats consume either a regular high-carb diet or a low-carb, high-fat diet for sixteen days. After this period the diets were switched and rats were maintained on the opposite diet for another sixteen days. Both diets included the same number of calories, so the only difference between the groups was the relative percentage of macronutrients.

As you might expect, while the rats were fed a low-carb, high-fat diet they lost weight compared to rats on a regular diet. Interestingly, however, despite this loss of body weight there was little to no loss of fat, and therefore the rats that lost weight had a relatively higher body fat percentage than the rats fed a normal diet.

The low-carb rats also had lower energy expenditure (exercise and calorie burning) than rats on a normal diet, and the decrease persisted even when the animals were returned to a normal diet. This is consistent with reports of exhaustion in humans undergoing very low-carb diet regimens.

Furthermore, animals that were temporarily put on a low-carb diet regained more weight than animals that were never fed a low-carb diet. This suggests that short term exposure to a low-carb diet increases risk of weight gain compared to no dieting.

Uh oh.

According to this research it is possible that a low-carb diet may actually cause you to gain weight in the long run. How very unfortunate.

But while these results are compelling, do not go stocking up on pasta just yet. First remember that these are rats, not humans. The way scientists change the composition of a rat’s diet is by giving them different pellets of bizarre lab food with various proportions of “nutrients.” This is not the way humans eat (assuming you don’t spend too much time in GNC), nor can it ever reflect a healthy human diet. It would be great if they could put the rats on a diet of seasonal fruits and vegetables, whole grains, legumes and fatty fish, but that is not the way animal research works. This is something to keep in mind whenever you hear about nutrition studies.

Also, nutrition research using rodents rarely distinguishes between the qualities of different macronutrients. For example, did the “high-fat” diet contain mostly saturated fat, trans fat, monounsaturated fats, polyunsaturated fats or all of the above? A similar question can be asked about the quality of carbohydrates, but it is difficult to imagine high-quality carbohydrates coming in pellet form. A huge body of scientific literature suggests that the quality of different macronutrients is far more important to health and weight than relative proportions of refined macronutrients.

Protein is another question mark in this study, which the authors acknowledge. The low-carb diet they used was not high in protein like a typical Atkins style diet. However, their findings were similar to studies that did use higher protein content and their animals were fed sufficient protein to maintain normal body growth, so the effect of protein on their findings is likely to be small. Their goal was to examine the effect of extreme carbohydrate restriction, and this was accomplished.

Regardless of this study’s imperfections, the results shine an interesting light on our current understanding of how relative proportions of dietary macronutrients effect body composition, long-term body weight and metabolism.

Have you experienced weight gain after going off a low-carb diet?

UPDATE: This article is also available at Synapse.

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