The best of the high-profile, commercially available diet programs is Jenny Craig, according to Consumer Reports.
The consumer magazine ranked seven of the most popular diets based on their nutritional soundness and ability to produce weight loss in the short and long term, and also examined their cost and complexity.
Jenny Craig was judged far and away the best, largely because clients lose weight and keep it off over a period of years and because it offers the best support system.
A study published last October in the Journal of the American Medical Association showed that 92 per cent of Jenny Craig clients stayed on the diet for at least two years, and they maintained an average weight loss of 8 per cent of their body weight.
Consumer Reports notes that all diets involve restricting calories because the only way to lose weight is to burn more calories than you consume. The magazine also cautions that many diets are very restrictive, making it difficult to stick with the program, so individuals need to find an approach that works for them.
Kathleen Melanson, associate professor of nutrition and food sciences at the University of Rhode Island in Kingston, R.I., said that, ultimately, the diet that works is the one a person can maintain over time.
"If you're forcing yourself on a diet you hate, it's going to be really hard to stick with long term," Dr. Melanson said.
Below is a summary of the findings:
RANKING THE BEST DIETS
1. Jenny Craig
Score: 85/100
Daily calories: 1,315
Concept: Caloric restriction made easy by following an eating plan consisting of branded products.
Cost: $399 (U.S.) a year plus food, about $160 weekly
Support: Weekly session with a counsellor
2. Slim-Fast
Score: 63/100
Daily calories: 1,125
Concept: Caloric restriction. Eat a branded Slim-Fast bar or shake for breakfast and lunch and a 500-calorie homemade dinner.
Cost: Shakes and bars are about $1 each.
Support: Online tracking is available free.
3. Weight Watchers
Score: 57/100
Daily calories: 1,865
Concept: Caloric restriction. You eat whatever you want but must adhere to a points system that is essentially based on calories.
Cost: Monthly meetings cost $39.95 in person or $17.95 online.
Support: Meetings and the support of others are the mainstay of the program.
4. The Zone
Score: 53/100
Daily calories: 1,260
Concept: A complex program of insulin-suppressing "anti-inflammatory" meals with numerous food restrictions.
Cost: $360 a month includes food and support; $74.50 a week for food alone
Support: Register free online or pay for personalized phone support.
5. Ornish
Score: 48/100
Daily calories: 1,525
Concept: Essentially a vegan diet, high in carbohydrates and low in protein. It is especially effective for heart patients.
Cost: The price of a Dean Ornish book, the most recent of which is The Spectrum.
Support: None, as the program is not marketed.
6. Atkins
Score: 48/100
Daily calories: 1,915
Concept: High-protein, low-carb diet is supposed to force the body to burn fat, not carbs.
Cost: None, unless a person chooses to buy an Atkins cookbook or branded products.
Support: Online forum and meal tracker.
7. Nutrisystem
Score: Not rated because of lack of studies.
Daily calories: 1,270
Concept: Caloric restriction based on consuming branded products.
Cost: $350-$430 a month for food
Support: Online support available at additional cost.
André Picard