But as an outsider, obesity in the US is obviously a consequence of the prevalence of junk food and the marketing power of the food industry. That doesn't soun

But as an outsider, obesity in the US is obviously a consequence of the prevalence of junk food and the marketing power of the food industry. That doesn't sound like the most scientifically-founded assertion to me, especially given that you're looking for scientific evidence for or against low-carbohydrate diets. I guess it also doesn't necessarily tell you whether low-carb diets are any good or not, so it's a red herring here. A really great book that points out many studies related to low-carbohydrate diets (especially experimental studies comparing against low-fat diets) is "The Art and Science of Low Carbohydrate Living". Written by two scientists who've spent their careers studying this, they point out that almost all studies which show poor results and undesirable side effects from a low-carb diet only last a few weeks - whereas it takes a few weeks for humans to adapt to a diet like that, so a study must necessarily get over that hump before making any conclusions. Furthermore, low-carb diets cause people to lose a lot of electrolytes, which is the main cause of bad side effects, and many studies do not tell their low-carb subjects to supplement with salts. Studies which last longer than a few weeks tend to show favorable outcomes, generally with fat loss exceeding low-fat diets and better adherence as well over the long-term. If you want more details, I'd recommend you get the book.