BigFatScience is giving very harmful advice, but I think part of the confusion is many doctors say stuff that is unhelpful or downright harmful.  Ask a doctor what they would say to someone who wants to lose weight and most say "eat less exercise more." First, no amount of exercise will help weight if you have a bad diet.  Exercise is good for your health, but has a tiny impact on your weight.  Once you are a competition level biker, runner, swimmer, or whatever then it will have an impact on your weight, but people looking for advice on how to loose weight aren't in that category. Second, how many doctors would recommend high protein low carb or intermittent fasting?  Both seem to work, but doctors will recommend low fat which just ends up being high carb. I think it is only logical for people to question their doctors advise.  Especially when a low fat diet was one of the recommended solutions by the medical community.  That is why these retarded blogs have so many followers.