Diet Plans - What the Studies Say

What the studies say

No need to wonder about losing weight on these diets; they’ve all been tested in clinical trials published in scientific journals. Plans are listed in rank order of overall score. Even the highest-rated diets generally produced less than a 10 percent weight loss after a year and had dropout rates of more than one in five participants. Weight Watchers, Jenny Craig, and Slim-Fast scores were very close together.

VOLUMETRICS
What it is Based on research at Penn State, diet aims to maximize the amount of food available per calorie, mainly by use of reduced-fat products, liberal addition of vegetables, and low-fat cooking techniques. Encourages first course of brothbased soup or low-calorie salad to take the edge off appetite. Pros and cons Recent clinical trials show best overall weight loss of any diet evaluated. We judged the recipes appetizing but somewhat time-consuming to prepare.
	Rating Overall score............... Study results Short term Weight loss............... Dropout rate............. 1 year Weight loss............... Dropout rate............. Nutrition analysis.............	Percent of calories Fat................................ 23 Saturated fat................. 7 Carbohydrates............. 55 Protein.......................... 22 Fiber, g/1,000 cal. .......... 20 Fruits & veg., daily serv.. 14 Average daily calories..... 1,500

WEIGHT WATCHERS
What it is Venerable program uses weekly meetings and weigh-ins for motivation and behavioral support for diet and exercise changes, or you can sign up for similar support online. Dieters either earn or spend “points” with food and exercise or consume specified foods with “Core” plan. Vegetarian menu available. Pros and cons Behavioral support is proven to increase adherence to any diet. Scored average on weight loss in this group but first in long-term adherence. We judged recipes to be appetizing and fairly easy to prepare.
	Rating Overall score............... Study results Short term Weight loss............... Dropout rate............. 1 year Weight loss............... Dropout rate............. Nutrition analysis.............	Percent of calories Fat................................ 24 Saturated fat................. 7 Carbohydrates............. 56 Protein.......................... 20 Fiber, g/1,000 cal. .......... 20 Fruits & veg., daily serv.. 11 Average daily calories..... 1,450

JENNY CRAIG
What it is Dieters sign up for individual counseling and meal plans at company outlets, by phone, or online. Centerpiece of diet is eating Jenny Craig prepared foods of single-serving entrées and snacks, supplemented by dairy, salads, and other vegetables you prepare yourself. Vegetarian menu available. Pros and cons Diet requires minimal food preparation and meets dietary guidelines. Published study of actual client histories revealed high dropout rate, though those who stuck with plan lost considerable weight. Clinical trial had better adherence.
	Rating Overall score............... Study results Short term Weight loss............... Dropout rate............. 1 year Weight loss............... Dropout rate............. Nutrition analysis.............	Percent of calories Fat................................ 18 Saturated fat................. 7 Carbohydrates............. 62 Protein.......................... 20 Fiber, g/1,000 cal. .......... 16 Fruits & veg., daily serv.. 6 Average daily calories..... 1,520

SLIM-FAST
What it is Brand line of controlled-calorie shakes and bars, widely available in drugstores and supermarkets. Company Web site provides weekly menus. On standard meal plan, a bar or shake for breakfast and lunch, with additional food. For dinner, a low-calorie meal you fix yourself. Pros and cons Menu we analyzed meets dietary guidelines. Convenient for people with little time or inclination to cook. Clinical studies show above-average long-term weight loss but high long-term dropout rate.
	Rating Overall score............... Study results Short term Weight loss............... Dropout rate............. 1 year Weight loss............... Dropout rate............. Nutrition analysis.............	Percent of calories Fat................................ 22 Saturated fat................. 6 Carbohydrates............. 57 Protein.......................... 21 Fiber, g/1,000 cal. .......... 21 Fruits & veg., daily serv.. 12 Average daily calories..... 1,540

eDIETS
What it is Well-established online subscription diet site offers 24 meal plans customized for various eating preferences and desired weight loss. Membership includes access to support groups, experts, menu plans, recipes. The standard eDiets.com weekly menu we analyzed met dietary guidelines and delivered the number of calories promised. Pros and cons Customizable plans are appealing, especially for those with wheat or lactose intolerances, but clinical studies find average adherence and below-average weight loss.
	Rating Overall score............... Study results Short term Weight loss............... Dropout rate............. 1 year Weight loss............... Dropout rate............. Nutrition analysis.............	Percent of calories Fat................................ 23 Saturated fat................. 5 Carbohydrates............. 53 Protein.......................... 24 Fiber, g/1,000 cal. .......... 19 Fruits & veg., daily serv.. 12 Average daily calories..... 1,450

THE ZONE DIET (men's menu)
What it is The “Zone,” as conceived by Barry Sears, is a the ideal balance of foods to keep your blood sugar and hormones ready to fight obesity and diseases. To stay in the Zone, every meal must consist of 30% fat calories, 30% protein, and 40% carbs. Diet allows many fruits, practically no grains except oatmeal. Pros and cons We judged the recipes simple to prepare and the meal plan to have a good nutritional profile, but figuring out the diet without a meal plan involves a lot of math. Weight loss below average.
	Rating Overall score............... Study results Short term Weight loss............... Dropout rate............. 1 year Weight loss............... Dropout rate............. Nutrition analysis.............	Percent of calories Fat................................ 27 Saturated fat................. 7 Carbohydrates............. 42 Protein.......................... 30 Fiber, g/1,000 cal. .......... 21 Fruits & veg., daily serv.. 17 Average daily calories..... 1,660

ORNISH DIET
What it is Ultralow- fat vegetarian regimen bans all meat, fish, oils, alcohol, sugar, and white flour. Ornish’s clinical studies have shown that strictly following the diet can prevent or reverse disease. He believes it’s easier to make drastic changes in diet than small ones. Pros and cons Provides the most food per calorie of any diet evaluated. Lower in fat than guidelines recommend. Studies show average long-term weight loss and below-average longterm adherence.
	Rating Overall score............... Study results Short term Weight loss............... Dropout rate............. 1 year Weight loss............... Dropout rate............. Nutrition analysis.............	Percent of calories Fat................................ 6 Saturated fat................. 1 Carbohydrates............. 77 Protein.......................... 16 Fiber, g/1,000 cal. .......... 31 Fruits & veg., daily serv.. 17 Average daily calories..... 1,520

ATKINS DIET
What it is This granddaddy of low-carb diets starts with a two-week induction period that bans practically all carbs. The longer “ongoing weight loss” phase is only slightly less restrictive, gradually adding more vegetables, fruit, and wine. Pros and cons There’s growing evidence that dieters aren’t as hungry on Atkins as on some other diets. But many find it too restrictive, so long-term adherence is below average; long-term weight loss is average. Its nutritional profile is far outside dietary guidelines.
	Rating Overall score............... Study results Short term Weight loss............... Dropout rate............. 1 year Weight loss............... Dropout rate............. Nutrition analysis.............	Percent of calories Fat................................ 60 Saturated fat................. 20 Carbohydrates............. 11 Protein.......................... 29 Fiber, g/1,000 cal. .......... 12 Fruits & veg., daily serv.. 6 Average daily calories..... 1,520

One study used was a longitudinal study of all enrollees in Jenny Craig’s premium plan for a one-year period, published in the February 2007 International Journal of Obesity.

Guide to the Ratings

Overall score is based on adherence to nutritional guidelines and the results of published randomized clinical studies (exception noted in footnote) that reported three- to six-month short-term and one-year long-term results and together studied at least 40 subjects per diet. Study results, including short- and long-term weight-loss and dropout rates, were derived from published studies of each diet. Nutrition analysis, done in 2005, was based on a week of menus from each book or program, using The Food Processor software from ESHA Research. For diets that had a short introductory phase and a longer weight-loss phase, we evaluated the latter. Higher scores went to menus that conformed most closely to the recommendations of the 2005 U.S. Dietary Guidelines for Americans: 20 to 35 percent of calories from fat, with less than 10 percent from saturated fat; 45 to 65 percent from carbohydrates; 10 to 35 percent from protein; more than 14 grams of fiber per 1,000 calories. Average daily calories and servings of fruits and vegetables are listed for information only and are not part of the overall nutrition score. Guidelines call for 6 to 9 servings in a 1,400- to 1,900-calorie diet.