Remember how back in high school and/or college you got to the nitty gritty of a difficult to understand novel by reading the “Cliff Notes?”  Well, just a FYI about a rather straightforward article in yesterday’s New York Times that summarized weight loss regimens based on cost, starting with the least expensive approach (zero dollars).  I thought the information in the article was pretty accurate and a good place to start for those who want to lose weight (like about 98% of people I know) but aren’t sure how to go about it.  Don’t be expecting to find some new sure-fire diet plan; it’s still all about motivation, calories in, and calories burned.

This week’s New England Journal of Medicine (Volume 359, No. 3, July 17,2008) contained an article entitled “Weight loss with low-carbohydrate, Mediterranean, or low-fat diet,” written by Iris Shai and colleagues. Although the study was conducted in Israel, it was a large international effort with co-investigators from all around the globe. The study results even made the New York Times (“Healthy diets shown to have benefit despite modest weight losses,” written by Tara Parker-Pope, Thursday, July 17, 2008, page C3).

The Study Design

The purpose of the study was to evaluate the effectiveness of several different diet plans long-term with an effort to minimize “drop-outs.” The investigators claimed (correctly) that most previous studies had been hampered by their short-term nature and/or large drop-out rates. The plan was to recruit slightly obese subjects from a single work-site and monitor them for 2 years. The investigators recruited 322 subjects willing to be randomly assigned to 1 of 3 dietary regimens: a low-fat, restricted calorie plan (group 1) ; a Mediterranean, restricted calorie plan (group 2) ; and a low-carbohydrate, non-restricted calorie plan, based on the Adkins diet (group 3). The mean age of study subjects was 52 years and the mean BMI was 31 (I’m sure you remember from previous entries that the BMI is calculated by dividing the weight in kilograms by the height in meters X height in meters; normal is <24.9, overweight is 25-29.9, and obese is 30 or more). Eight-six percent of subjects were male. The study subjects had intensive education regarding the diet plans and frequent follow-up.

The Results

First, adherence to the regimens (I think that meant that the study subjects showed up for their follow-up visits?) was pretty good, about 95% after 1 year and 84.6% after 2 years (272 out of 322 subjects). For each study group the maximum weigh loss was between 1-6 months into the study. At the end of the study, the mean weight loss in subjects who completed the study was 3.3 kg, 4.6 kg, and 5.5 kg in groups 1-3, respectively. The mean BMI fell by 1 in group 1 and 1.5 in groups 2 and 3. There was a difference in results comparing males and females; the 45 females in the study lost 0.1 kg in group 1, 6.2 kg in group 2, and 2.4 kg in group 3.

The investigators found no particular safety problems with any of the diet plans. The subjects with diabetes mellitus fared best with the Mediterranean diet plan in terms of improved fating plasma glucose values (the improvements in hemoglobin A1cs were about the same in the 3 groups, about 0.5%). Lipid profiles showed modest improvements with all 3 diet plans but group 3 (the low-fat diet group) generally showed the greatest improvements.

The investigators concluded that based on their results, Mediterranean and low-carbohydrate diets may be effective alternatives to “classic” low fat diets. They also concluded that a workplace medical care model for weight reduction such as in their study might be a useful way to achieve beneficial results and that even modest weight reductions can improve risk factors for undesirable health outcomes. The investigators did not really focus on the benefits of one diet plan vs. another (I do wonder what the first draft of the paper submitted to the journal looked like, but we’ll never know).

What do the results mean?

I found it somewhat difficult to interpret the results. First, the investigators should have presented the male and female data separately given the fact that 86% of the subjects were male but also given the results in the 45 female participants; the females lost quite a bit more weight on the Mediterranean diet (average of 6.6 kg) than on either of the other 2 plans. In fact, the females lost only a trivial amount on the other 2 plans. I have no idea what the data mean except that we should think twice before trying to generalize the study results to males and females alike.

The investigators are to be commended for having a pretty low drop-out rate but even 15% is of concern. In addition, the data showed that the drop-out rate differed among the 3 groups- it was highest in the low-carbohydrate group (22%) and lowest in the low-fat group (9.6%) with the differences statistically significant.

Finally, even two years of follow-up is far too brief a period of time to come to any firm conclusions about long-term effects of the of the 3 diet plans with respect to efficacy and safety.

What do the results really mean?

If one takes a hypothetical study subject with a BMI of 31, it might be a male about 175 cm tall (almost 69 inches tall) who weighs 95 kg (209 lbs). To attain a weight at the upper limit of the “normal” BMI range (24.9) he would need to lose about 18 kg, far more than was achieved in the study conducted by Shai and colleagues. Clearly, even heroic efforts to achieve weight loss by dietary manipulation as undertaken by the investigators still fall far short of what is desirable. But, still, every little bit helps. I do wonder what the results would have been in study subjects with much higher BMIs?

I just finished reading two interesting articles and an accompanying editorial published in the December 6, 2007 issue (subscribers get the issues a few days before the official publication date). The first article is entitled “Childhood Body-Mass Index and Risk of Coronary Heart Disease in Adulthood,” written by Jennier L. Baker and colleagues from the Institute of Preventive Medicine, Center for Health and Society in Copenhagen, Denmark (N Eng J Med 2007;357:2329-37). The second article is entitled “Adolescent Overweight and Future Adult Coronary Artery Disease,” was written by Kristen Bibbins-Domingo and colleagues from the Departments of Medicine, Epidemiology and Biostatistics, and Pharmacy at the University of California, San Francisco and San Francisco General Hospital and the College of Physicians and Surgeons, Columbia University. The editorial was entitled “Childhood Obesity- the Shape of Things to Come,” written by David S. Ludwig.

Both studies showed essentially the same thing- that overweight adolescents become overweight adults and develop serious complications associated with the overweight. There is really nothing new here except that the data are rather alarming and will, I hope, dispell the curent trend in the press to suggest that being overweight isn’t all that bad. I even heard a piece on NPR this afternoon about a study of people with BMIs up to 35, that apparently showed even rather obese people are in good enough condition to “pass” the treadmill test.

Wake up America

We as a society are exceedingly good at basically ignoring scientific data we don’t like. Whether it’s data about global warming, the high prevalence of people who do not have health insurance, or obesity, we work hard to find reasons to ignore the data. With respect to the obesity epidemic, we are particularly adept at giving only token consideration to the serious health issues. I continue to be amazed by the fast food ads on TV, which push higher and higher calorie (mostly fat) meals. Of course, the fast food indiustry knows that we haven’t really changed our eating habits a bit, despite the obesity data, and that the megameals sell.

So, what can we do?

The editorial accompanying the articles is pretty tame but it does summarize what most people already know about the prevalence and health risks of obesity. It is worth reading but isn’t particularly inspiring. I actually have no idea what would be inspiring. But I do urge physicians to stop burying their collective heads in the sand and let their patients know that obesity is bad for all of us, whether child or grown-up, and that we should develop individual prevention/treatment plans NOW, if we are to avoid disaster later. Does that mean I can’t have a triple cheeseburger tonight (maybe I’ll skip the fries)?

There was an interesting article in The New York Times today (Wednesday, September 5, 2007). The article was entitled “The School Cafeteria, on a Diet,” and written by Andrew Martin. It is probably noteworthy that the article appeared in the Business Day section of the newspaper; there is quite a lot of money at stake for soda drink manufacturers and for the schools themselves given how much revenue schools currently generate from sales of mostly soda drinks and other “junk” food.

What’s wrong with school food?

I remember the good old days, when for one thin dime, a guy could buy two slices of white bread smothered in gravy for his school lunch. Those days are long gone as schools are beginning to consider offering reasonably nutritious meals. There is considerable pressure to do this, prompted mostly by the alarming data on rates of childhood obesity (about 20% of children 6-18 years of age based on data from the CDC). According to the article, there is a federal requirement in place that mandates each school district develop a wellness plan to help students eat healthier foods. Such federal rules have already been in place for some time for the subsidized lunch program- remember, tomato ketsup is considered a vegetable! I am pleased to learn that under current federal guidelines jelly beans and Popsickles are banned because they have “minimal nutritional value,” while Snoickers and Dove bars are “in” because they contain some nutrients. Can they really be serious about this?

How can we bring some measure of good judgment to all of this?

I think it’s just fine that the schools improve their food offerings, both in the school cafeteria and in their snack machines. Actually, I would recommend that schools eliminate the snack machines entirely (oh, I know you need the revenue). I can’t think of any good reasons why students shoul be buying snacks during the school day, even “healthy” ones. Also, there is the cost factor- have you ever calculated how many peanut butter crackers a student could bring from home for the cost buying of a package of 3?

One big problem is how do we decide what is nutritious vs. not nutritious? To say that a Dove candy bar is more nutritious than jelly beans is ridiculous. They are both highly processed foods which raises another whole set of issues. But, for example, there are no convincing data to show that jelly beans or sugar-containing sodas are less nutritious than any other food with the same quantity of carbohydrate. Also, what’s wrong with pizza? Children like it better than tofu (for the record, I like tofu just fine).

I contend that we are not going to have any significant impact on childhood or adult obesity by focusing on the quality of school lunches, at least the way we have been approaching things. Did you know that data show it is on vacations from school that children gain the most weight! The problems are deep-seeded and we should be careful of what we expect the schools to do in terms of public health (is obesity a public health issue?). The schools have been very effective in promoting better childhood immunization rates (e.g., “your kid can’t go to school without the following immunizations…..”).

I don’t think the schools can help very much with our obesity problems unless there is a broad educational effort on both nutrition and physical activity starting at the kindergarten level and continuing through high school. Maybe we could even reintroduce regular physical education classes- many schools now offer little or no physical education. We need to teach what is good nutrition (of course, no one can agree on what that is) and how to eat in a healthful manner. I think it is much less important that the school food offerings be what some expert panel decides is nutritious, but rather, what children are likely to be willing to eat, with an emphasis on more fruits and vegetables and fewer processed foods (not easily done since the highly processed foods tend to be the least expensive to serve).

Doesn’t anybody bring lunches from home anymore?

One last thing. I encourage many of my patients, particularly those with diabetes or problems with overweight, to bring lunch from home. First, it’s much cheaper than buying school lunch (unless one has a free or reduced cost lunch funded by the feds). Also, the child can help select the foods and the parents can encourage the child to eat a reasonably balanced meal. In some instances, there are powerful social pressures to eat school lunch rather than to bring lunch from home. I don’t know what to do about that problem. One big plus for home-prepared lunches are the cool lunch boxes that are available (if I still ate lunch at school, I’d surely want to bring my lunch from home- I now know that bread and gravy is not a great lunch choice- and I’d get a Star Wars lunch box).

The “buzz” today among medical journalists is about an article published today (available to subscribers and news organizations yesterday) in the New England Journal of Medicine. The article was written by Nicholas Christakis and James Fowler and entitled “The Spread of Obesity in a Large Social Network over 32 Years.” The citation is New Engl J Med 2007;357:370-9. There was an article about the study today in the New York Times ( “Find Yourself Packing It On? Blame Friends,” written by Gina Kolata- Thursday July 26, 2007, page A1). There was also a piece on National Public Radio. I’m sure this study will be widely reported on.
The scientists studied a network of people who were part of the famous Framingham Heart Study which was initiated in 1948. The authors actually started with the “offspring cohort” from the original Framinham subjects (n= 5124) and created a network data set which included both original Framingham study subjects and offspring cohort subjects. Linkage between the offspring cohort subjects (called “egos”) and other Framingham study subjects (called “alters”) was based on marriage, sibship, and friendships. A total of 12,067 people ended up as either egos or alters.

So, what’s with these egos and alters?

The authors took their carefully constructed social network and studied if obesity was related to the linkage, much like one might study epidemiology of an infectious disease. Obesity was defined as a BMI 30 or greater (if you forgot what a BMI is check out one of my earlier entries). The study included only people older than 21 years of age. The average age of the study subjects at the start of the study was 38 years and 53% of the subjects were women. The data collection was from 1971-2003. The 5124 egos from the offspring cohort had 38,611 observed family and social ties (e.g., spouse, neighbor friend).

The authors found that obesity in this study population was in clusters related to the social contacts. Thus, if a person (the ego) had a friend (an alter) who became obese during the period of observation, the ego was 57% more likely to also become obese. If the friend was a “close friend,” the risk was increased by 171%. Risks were increased with sibs and spouses but not with friends of the opposite sex or with neighbors. So, what this all means is that having a friend or a spouse or a sibling who is or who becomes obese, means that you are much more likely to also become obese. The converse is also true; if one’s relations and friends are lean, he is more likely to remain lean.

Ok. Now what?

I find the data interesting but not so surprising. Many previous studies have demonstrated, at least within families, the effects of parental obesity on their childrens’ weights independent of genetic influences. The authors of the study speculate that the social influence on the spread of obesity can perhaps be “harnessed” to to slow the epidemic. The authors are a bit fuzzy as to how this actually might be accomplished. It would appear from their data that the best approach would be to have people at risk for obesity (most Americans) or those who are already obese hang out only with thin people. Of course, some of those thin people might be smokers and the person hoping to avoid the bad influence of being around someone who will become or who is already obese might be trading one “evil” for another.

When and if all of this ever gets sorted out, I think it is likely we will find that there are many reasons for the observed clusering of obese people. For some it will be shared acceptance of the obesity resulting in less anxiety about the problem. For others, it will be similar lifestyles, eating, and exercising habits that promote the obesity. I doubt many friendships are based on the idea that “opposites attract.” People generally want to be around people who are like them. I view the data as just one more interesting piece of information about the environmental causes side of the obesity epidemic (the other side is genetics). Whether we can take these data and use them to help people trim down other than by abandoning their overweight friends and relations remains to be seen. I for one intend to screen my new prospective friends by having them submit their BMIs to me for review.

So, did you know most of the answers to the nutrition quiz I gave you yesterday? The Hostess Twinkies question was just for fun and I wouldn’t have expected you to know the answer.

1. What is a trans fat- trans fats are unsaturated fats that have been modified by adding hydrogen atoms to them making them more saturated. The term “trans” refers to the way the molecule bonds are configured (bonds can be cis or trans). Trans fats were first synthesized in the early 1900s and their special virtue is that they tend to stay solid at room temperature, making them ideal for processed foods. I think Crisco was the first commercially available trans fat product but I’m not certain. Trans fats are typically made from plant fats, particularly those derived from corn and soy beans. Your Hostess Twinkie wouldn’t be so appetizing if the fat used to make the product was in a liquid form sloshing around in the package. Trans fats are a problem only because they are associated with a greatly increased risk of heart disease. That has turned out to be enough of a problem that food manufacturers are working hard to find ways to make various food products withoiut having to use trans fats. I think New York City has banned trans fats in restaurants and many fast food chains have or are figuring out how to eliminate trans fats in their products. Personally I don’t believe that eliminating all trans fat-containing foods will have much of any impact on health given the very small percentage of total fats we consume that have been trans fats. But, why not?

2. How many calories per gram of fat, carbohydrate, and protein and so what? The answers are 9 calories per gram of fat and 4 calories per gram for carbohydrates and proteins. That means fats really concentrate the calories and that’s not good if one eats lots of fats and is concerned about weight. In scientific terms, it’s a good thing fats pack a lot of calories for the weight- just think how much people would weigh if they maintained the same energy stores as now but doing it in the form of protein or carbohydrate- it would be a disaster. So, think of fat as an engineering marvel not as an unsightly body component (it is also a great insulator on those cold winter days).

3. Supermarkets and corn- about 70% of foods at the supermarket are in part corn-derived. That’s pretty amazing. Much of the corn is in the form of high fructose corn syrup.  That figure also includes the portion of meats that are in part corn-derived (all that “corn-fed beef”).  Scientists can actually track the carbon molecules from corn and see how much of whatever food has the corn carbons.  If we are what we eat, we are mostly corn.

4. Calories and grams of sugar in a “regular” soda- a standard 12 oz soda has about 41 grams of sugar (mostly from high fructose corn syrup) or 8 teaspoonfuls for about 160 calories.

5. Twinkies- according to a program I watched on the Travel Channel the other day, last year 500 million Twinkies were eaten in the U.S.  That’s about 80 billion calories if my math is correct. Wow.  By the way, they get the cream inside the Twinkies by injecting the cream through the bottom of the Twinkie.