It is a lifestyle change, but it's actually far more likely to be successful than the FA people like to claim. It seems many people - once they've decided to make a change and have reduced their weight - are perfectly able to stick to it. Here is a paper on the subject: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4777230/ One of the studies:  In 2014, Thomas et al4 reported a 10-year observation of self-reported weight loss and behavior change in 2,886 participants, recruited primarily through newspaper and magazine articles, who had lost at least 30 pounds (13.6 kg) and kept it off for at least 1 year. The mean weight loss of participants was 31.3 kg at baseline, 23.8 kg at 5 years and 23.1 kg at 10 years. Of note, 87% of participants were still maintaining at least a 10% weight loss after 5 and 10 years.   While the record wasn't perfect, that shows that the vast majority (87%) were able to make a positive change to their lives and stick to it for at least 10 years. (Obviously as the observation period was 10 years, that's all which can be claimed by the study.)