Actually no it NOT that simple. Have you perchance read the work of Dr Traci Mann? She analysed the metadata of every randomised study of dieting greater than 2 years. She subsequently added data from additional studies a few years later. What she reported was:

“The results were clear. Although dieters in the studies had lost weight in the first nine to 12 months, over the next two to five years, they had gained back all but an average of 2.1 of those pounds. Participants in the non-dieting waitlist control groups gained weight during those same years, but an average of just 1.2 pounds. The dieters had little benefit to show for their efforts, and the non-dieters did not seem harmed by their lack of effort.”

There is also another study relating to childhood trauma:

Researchers at the Karolinska Institutet in Sweden recently conducted a meta-analysis of previous studies, which included a total of 112,000 participants, and concluded that being subjected to abuse during childhood leads to a marked increase in the risk of developing obesity as an adult.

If you take time to look beyond studies funded by the diet industry you’ll find a very different picture.