> The evidence says otherwise. “Even if someone loses weight, they will always need fewer calories and need to exercise more,” says Skinner. “So we’re putting p

> The evidence says otherwise. “Even if someone loses weight, they will always need fewer calories and need to exercise more,” says Skinner. “So we’re putting people through something we know will probably not be successful anyway. Who knows what we’re doing to their metabolisms.” There has been evidence of previously morbidly obese people having a severe metabolic impact, where they need to consume around 500 kcal less a day than someone with their body composition who had not been morbidly obese. This is observed to be independent of appetite - it is not uncommon for people who have lost large amounts of weight to constantly have to eat smaller portions while closely monitoring their intake (count calories) to keep weight off long-term. The last I read about this (three years ago?), there were investigations into how techniques like intermittent fasting might impact this. This is IMHO a general problem with the weight loss industry and weight loss oversimplicications like 'calories in, calories out' - we aren't simple furnaces, and there are endocrinological factors that are very important that such simplifications have caused us to ignore. The most obvious evidence I can point to here is around bariatric surgery for morbidly obese patients. There are many temporary and permanent solutions (e.g. folds, inserting balloons, etc), but generally only the permanent removal of stomach tissue has been shown to have permanent weight loss impact. This has led to additional study on the impact that the hormone ghrelin, produced by the stomach tissue itself, has on appetite, energy storage, insulin sensitivity, etc.