Of course there's differences in how the body metabolizes different macros, and I'n not saying that certain diets aren't going to "work" for certain people. He

Of course there's differences in how the body metabolizes different macros, and I'n not saying that certain diets aren't going to "work" for certain people. Here's my specific points 1- In many parts of the developed world where food scarcity has been minimized/eliminated, we see increased rates of obesity across all demographics. This is a messy knot of factors that covers everything from social behaviors to availability of nutritious food to education and wealth. If you're going to tackle "why are people so much more likely to be obese than before?" you have a TON of factors to attempt to control for in the decision making. 2- If you're not trying to figure out why people are making their choices, and looking at it from a strictly "how does the body work and is that contributing" the simple answer is: your body more readily converts various carbs into body fat than any other macros (Protein, Lipids, Alcohol), people eat a lot of carbs, and finally most people tend to overeat if presented with more food than they actually need. This is the basic scientific consensus, and explains why your experience with a keto diet was positive. The issue is, as you said, that people are interested in selling meal packages and books and lifestyles and generally getting rich off other people's body image issues/health problems. Carbs play a part of in the obesity spike in recent years, but WHY people eat the way they do is what we need to figure out if we want to solve things.