An article in Annals of Internal Medicine review concluded that “weight loss is modest and likely below patients’ expectations.”

Researchers reviewed 45 U.S. trials evaluating 11 programs: Weight Watchers, Jenny Craig, Nutrisystem, Health Management Resources (HMR), Medifast, OPTIFAST, Atkins, The Biggest Loser Club, eDiets, Lose It!, and SlimFast. These programs were compared with controls, which generally provided traditional counseling and education.

At 1 year, only Jenny Craig and Weight Watchers were able to show even modest weight loss compared with controls: 4.9% greater weight loss with Jenny Craig, 2.6% greater with Weight Watchers. Nutrisystem and very low calorie programs (HMR, Medifast, OPTIFAST) resulted in short-term (3–6 months) — but not longer-term — weight loss.

The editorialist writes that the study “highlights something that researchers … have known for decades: Structure and intensity of contact are highly correlated with program success. It is unsurprising that highly structured programs with in-person social support, such as Weight Watchers and Jenny Craig, seem more effective in the long term than less structured interventions.”.

Source : Ann Intern Med. 2015;162(7):501-512. doi:10.7326/M14-2238.

Appeared in NEJM Journal watch on April 7,2015

Note: Leptin: A hormone produced mainly by adipocytes (fat cells) that is involved in the regulation of body fat. Leptin interacts with areas of the brain that control hunger and behavior and signals that the body has had enough to eat, and until one lowers leptin level is not likely that a fast diet will succed at all since it is not able to lower leptin levels as the we shed weight. Antileptin are promising but not here yet.