The Obesity Society, the American Heart Association, and the American College of Cardiology have recently release their 2013 AHA/ACC/TOS Guideline for the Management of Overweight and Obesity in Adults (free full text available here). Dr. Arya Sharma has had a look and offers that the report is “big on how little we know” (emphasis mine):
[The report shows the] rather poor level of evidence that exists for virtually all of the dietary recommendations. …
Thus, low fat approaches appear no better than high-fat (strength of evidence: “moderate”), while the evidence in support of low-calorie diets, complex vs. simple carbs, glycemic load, Mediterranean-style diets, lower-fat lacto-ovo-vegetarian or vegan-style, or lower fat high dairy/calcium with added fiber and/or low glycemic index/load foods, use of liquid and bar meal replacements, or even very low calorie approaches is largely “insufficient” to make any reasonable recommendations in favour of any of these strategies versus any other.
Not that people do not lose on any or all of these diets as long as they are “energy restricted” – of course they do!
But, what is lacking is evidence that any of these countless dietary approaches confer any meaningful advantage (in terms of amount of weight lost, metabolic benefits or sustainabilty of weight loss) compared to any other.
So, whilst millions of “bestseller” diet books may continue to make millions for their authors and publishers by touting one revolutionary weight loss solution after another, they are essentially closer to religious belief systems than scientific fact. …
Perhaps, what we need to accept, is that there simply is no “superior” dietary approach to managing your weight – it’s whatever works best for you.
I suspect that the real trick is for susceptible folks to figure out a way to exist in an environment that strongly promotes obesity. Eliminating fat or carbs or meat may not be sufficient. And for some, it may not be worth perpetually tilting at windmills.