• The end of diet debates

    I’d just post the whole thing if I could. “A Call for an End to the Diet Debates” (emphasis mine):

    As the obesity epidemic persists, the time has come to end the pursuit of the “ideal” diet for weight loss and disease prevention. The dietary debate in the scientific community and reported in the media about the optimal macronutrient-focused weight loss diet sheds little light on the treatment of obesity and may mislead the public regarding proper weight management. Numerous randomized trials comparing diets differing in macronutrient compositions (eg, low-carbohydrate, low-fat, Mediterranean) have demonstrated differences in weight loss and metabolic risk factors that are small (ie, a mean difference of <1 kg) and inconsistent. In the past year alone, 4 meta-analyses of diet comparison studies have been published, each summarizing 13 to 24 trials. The only consistent finding among the trials is that adherence—the degree to which participants continued in the program or met program goals for diet and physical activity—was most strongly associated with weight loss and improvement in disease-related outcomes. The long history of trials showing very modest differences suggests that additional trials comparing diets varying in macronutrient content most likely will not produce findings that would significantly advance the science of obesity. Progress in obesity management will require greater understanding of the biological, behavioral, and environmental factors associated with adherence to lifestyle changes including both diet and physical activity.

    Macronutrient content may influence dietary adherence via the satiating properties of protein, carbohydrates, and fat. However, dietary content is only one of many factors influencing adherence. The assumption that one diet is optimal for all persons is counterproductive because this assumption ignores the variation in adherence influenced by food preferences, cultural or regional traditions, food availability, and food intolerances. These are independent of direct physiological effects of macronutrient composition on weight loss. The most important question is how to improve behavioral adherence.

    The authors believe there are two reasons people push specific diets. The first is commercial; if you can sell a specific diet, you can make a lot of money. The second is that lifestyle interventions are assumed to be ineffective. We want a quick fix, and we’re always sure it’s just out of reach.

    I’ve said it before, and I’ll say it again. What works is very different from individual to individual. That’s important, because what works is what you can stick to. In other words, the specific diet isn’t as important as finding one to which you can adhere.


    • There is evidence that malnutrition is a problem even among obese dieters. Many dieters are simply restricting themselves to too few calories–1500 a day for an adult is probably counter productive, as muscle and bone tissue will be broken down to make up the difference. If muscle tissue gets broken down for energy, for example, this could make them more vulnerable to heart attacks, offsetting some of the heart-healthy benefits of loosing weight in the first place.

      I think a new diet paradigm could help. The aim should not be to loose weight per se, but to replace most fat weight with muscle weight–reducing waist size is perhaps a better metric than weight. That means more protein intake than current recommendations. Also, fiber does seem to have a surprisingly large effect in reducing cholesterol.

      So, my hypothesis is that dieters should maintain a diet over 1800 calories, and take a multivitamin, as well as fiber and protein supplements. Add in ample exercise, and beyond that, I’m not sure it matters a whole lot what they eat. Of course, this is assuming that longevity is the aim. More likely people just care about loosing weight fast.

    • While I don’t question the specific study – I do question the conclusion.

      I do think the evidence is pretty clear that we suffer from a pro carb – anti fat bias that is not fact based. After years of yo yo dieting I lost 125 pounds by restricting my daily carb intake and have kept it off for almost two years by managing carb intake.

      As with many things this is rooted in “politics” – the grain farmers “won” and they designed the food pyramid and we are living with the results.

      So yes – there are a lot of bad studies out there that don’t show the impact of carb management – or show it well – the data is out there if you look for it.

      • The difference between anecdote and data is that the data shows that no one diet works for everyone. Low carb worked for you. Maybe low fat works better for someone else.

        Low carb for many people probably boils down to portion size. Low fat to calorie density. Is your problem eating too much popcorn or is it the quantity of butter on your popcorn?

        Most people have to deal with both. What works will often boil down to whether they have an easier time eating a tiny portion of buttered popcorn or eating a normal portion of plain popcorn.

        • SAO,

          I don’t think we disagree much – and Aaron is right – adherence is the key…

          I lost weight – and have kept it off because I adhere to the low to moderate carb regime. I do think that the data on the relationship between carb consumption and weight gain/loss is pretty compelling – but that is subjective and others would [and do] disagree.

          I do believe that we may want to take a step back and rethink what we mean by obesity – we tend to worship at the holy grail of BMI way too much IMHO…

          I still have a BMI above 25 [I spent some time asking and looking for a study or two on why 25, but have yet to find one] And the cynic in me has always been suspicious of the nice round numbers we use to define underweight, overweight and obese.

          My body fat is 15% – and that is considered to be pretty good for someone my age.

          We tend to like simple – but pretty arbitrary measures – and far too often use them to make moral judgements IMHO.

    • We are OK with anything that allows us to blame our overweight on someone other tan ourselves, like those food producers and restaurants who put too much carb or too much fat in the food they sell. We do not want to hear that we just need to consume fewer calories.

    • This is basically the advice about exercise that Covert Bailey (“Fit or Fat”) has been giving for decades. When asked what the best exercise is, his answer is “the one you’ll do.” He definitively has opinions on certain types of exercise, but if you’ll swim and not run, then swimming is the best exercise for you. .

    • Any diet that can be adhered to will work. Otherwise we eat the same meals over and over, place the same portions on our plates, snack at the same daily time on the same products, and just generally trudge along in the same rut. Giving up animal products, meat, gluten, carbs, or fats forces us to rethink what we are eating and pay attention, for a while at least, to portion size while at the same time making snacking much harder. The rise in obesity starting in the 80s doesn’t correspond to the rise in fat panic of the 60s, HFCS, or any of the other past or present popular theories. It does correspond to more moms in the work force (a good thing!) and more meals eaten on the fly, more snacking, more soda, more TV channels (there were 5 or so when I was a kid), more two car families, more fear of children walking to school.

      Around 1970 my mom brought home a new product — soda in a 2 liter bottle. We laughed at it because it was such an outlandishly huge amount of soda. How could a family of four possibly drink all that? When I was in medical school many years later, my obese roommate drank 1-2 of those bad boys every day. Had those bottles been sweetened with the purest of cane sugar, she still would have been fat. (Sadly, she had no idea how to prepare a rational diet for herself and she enjoyed calorically dense fast food.)

      TV is an enormous appetite driver too. (Hey you kids, get offa my lawn.) Food products make up a much higher percentage of advertising than they did in the 1960s. These ads are filmed in pornographically loving detail and even if they don’t sell you on the product, they rev up your brain to go into food seeking mode. Exposure to hours every day makes resisting food between meals really hard. Again, when I was a child Julia Child had a breakthrough show with the first successful cooking show that appeared once a week. Now we have mutiple channels of food shows available 24/7. Food as recreation.

      Obesity is caused by far more than macronutrient selection.