Simple: There isn’t a proven, permanent method of weight loss that works for all (or even most) people.
Yes, most dieters lose 5-10% of their body weight in the first few months. They then regain some or all in the long term. This has been shown by a number of studies, including studies run by diet companies. (PDF) Depending on how long dieters are tracked after the study, usually 1/3 to 2/3 end up regaining all they lost, plus more.
So the real question isn’t, “Should I lose weight?” The real question is, “Would a small, temporary weight loss be worth it to me, and how much do I think I will regain? Do I think I will sustain a net loss, or will this just result in me weighing even more than I do now?”
I’m not saying people may not decide to go for it, and there are people who essentially “win the lottery” and both achieve and maintain a huge weight loss. But it’s not as simple as “Oh, I’m going to lose weight now”.
In my case, I also have a proven history; every diet has resulted in me weighing more than when I started. Every one. In fact, my weight gain as an adult has ALL been related to either clinical depression or dieting. Sobering? Yes. But that is my history and ignoring it won’t magically make diets work any better.
- Medicare’s Search for Effective Obesity Treatments: Diets Are Not the Answer (PDF) by Traci Mann et al, published in the April 2007 issue of American Psychologist.
- Health at Every Size: New Hope for Obese Americans?, by Marcia Wood, published in the March 2006 issue of Agricultural Research magazine. Highlights a 1-year study with 1-year followup comparing HAES with dieting. The dieters lost weight initially but gained it all back by the 2-year mark.
- Weight Loss for the Obese: Panacea or Pound-Foolish?, by Glenn A. Gaesser, QUEST, 2004, National Association for Physical Education in Higher Education.
- Dietary Therapy for Obesity: An Emperor With No Clothes, by Allyn L. Mark, Hypertension, 2008, American Heart Association.
- Health at Every Size: The Surprising Truth about Your Weight by Linda Bacon, PhD. Very readable discussion of healthy living and intuitive eating, but also discusses the research on dieting (and how it fails) in detail. About Linda Bacon -o- Book Website -o- Available on Amazon.com -o- My review is here.