A recent Alberta Tools for Practice1 suggests that “At best, ketogenic diets help patients lose ~2 kg more than low-fat diets at one year, but higher quality studies show no difference. Weight loss peaks ~5 months but is generally not sustained. There are no randomized controlled trials (RCTs) on mortality or cardiovascular disease. An individual's weight change can vary -30 to +10 kg with any diet.”
We tend to see individuals in the early stages of these diets losing weight with the enthusiasm of a new diet. However we really need to see longer-term studies with hard outcomes to be sure this diet regime is a viable solution for our patients. This is an absence of evidence situation.