Weight-loss programs: how effective and safe are they?

There are a number of commercial and other weight loss programs available to help you achieve a healthy weight. Below we provide brief descriptions of these programs, including their characteristics, effectiveness, and safety in people with type 2 diabetes.

Information on selected weight loss diets

Type of diet

Characteristics

Effectiveness

Safety

Jenny Craig
  • Portion-controlled, balanced, low-fat, low-calorie (1,200-1,300)
  • Purchase of pre-packaged meals required, supplemented by vegetables, fruits
  • Nutrient contents: carbo (50%-60%), fat (20%-25%), protein (20%-25%)
  • Includes nutritional counseling, exercise, social support
  • No rigorous studies for weight loss or disease prevention
  • Rated 3 out of 5 stars by experts for use in people with diabetes*
  • No data on safety in people with diabetes
Weight Watchers
  • Offers range of balanced, low-fat, low-calorie diets, tailored to individual needs and preferences
  • Uses strategy of assigning points to different foods based on calorie content and other factors
  • Participants assigned a daily point target
  • Program involves weekly meetings, providing community support mechanism
  • No rigorous studies for weight loss or disease prevention
  • Rated 3 out of 5 stars by experts for use in people with diabetes*
  • No data on safety in people with diabetes
Atkins
  • Limits carbohydrate consumption to 20 grams daily (most from high-fiber vegetables)
  • Increases consumption of protein and fats (egg, meats)
  • No rigorous long-term studies
  • Rated 2+ out of 5 stars by experts for use in people with diabetes*
  • Not recommended by ADA due to safety concerns
Paleo (Caveman)
  • Diet consists of wild meat, fish, eggs, fruit, berries, vegetables, and nuts
  • Carbohydrate consumption low (about 23% of total calories) and fat high (about 39% of total calories)
  • No scientific evidence to support use for weight loss or treatment of diabetes
  • Rated 2 out of 5 stars by experts for use in people with diabetes*
  • No data on safety in people with diabetes
Very low-calorie
  • Diets limiting daily calorie intake to 200-800 calories
  • Total daily calorie intake below 200 calories are referred to as “starvation diets”
  • No evidence of superiority to conventional diets in long-term weight loss
  • No data on safety in people with diabetes
Ornish
  • Promotes a low-fat, vegetarian pattern of eating: daily calorie totals fat 10%, carbohydrates 70-75% protein 15-20%
  • Stresses importance of eating such foods as beans, vegetables, fruits, and whole grains, and limiting consumption of processed foods, sugar, alcohol, and high-fat dairy products
  • Encourages regular exercise and stress reduction methods
  • Highly effective in reducing the risk of heart disease and reducing both high blood pressure and high blood cholesterol
  • Rated 3+ out of 5 stars by experts for use in people with diabetes*
  • No data on safety in people with diabetes
DASH
  • Designed by the US NHLBI, based on the USDA updated Food Pyramid, for the purpose of reducing blood pressure
  • Promotes increased consumption of vegetables, fruits, and low-fat dairy products while limiting consumption of total fat, saturated fat, cholesterol, and sodium
  • Variety of DASH diet tools are available for free from the NHLBI
  • Shown to be effective in weight loss
  • Top rated weight-loss diet by US News and World Report Expert Panel*
  • 3+ out of 5 stars for effectiveness in people with diabetes*
  • Diet generally reflects the dietary advice of ADA

Based on evaluation of by US News and World Report panel of experts.  National Heart, Lung, and Blood Institute=NHLBI; US Department of Agriculture=USDA; Dietary Approaches to  Stop Hypertension=DASH; American Diabetes Association=ADA

Jenny Craig diet

The Jenny Craig diet is a well-known, commercial weight loss program based on a portion-controlled, balanced, low-fat, low-calorie diet using pre-packaged meals (eg, frozen meals, nutrition bars). Nutrient contents of pre-packaged meals are carbohydrates (50% to 60%), fats (20% to 25%), and protein (20% to 25%). Individual diet plans are tailored according current weight, fitness, and other personal factors and daily calorie intakes can range from 1,200 to 1,300.1,2

Originated in Australia in 1983 (it began US operations in 1985), the Jenny Craig diet is a three-stage, food-mind-body plan combining diet with other elements including nutritional counseling, social support, and exercise, designed to give participants the skills and resources for long-term weight loss. Originally focused on a low-calorie diet to achieve rapid weight loss, the program has evolved and remodeled its pre-packaged meals along the lines of the US Department of Agriculture (USDA) updated Food Pyramid. Purchase of pre-packaged meals (sold exclusively by Jenny Craig, Inc. via phone, mail, or online) is required during the early and middle stages of the program. The company claims that the meals have been designed in consultation with health experts. Participants are advised to supplement the pre-packaged meals with fruit, vegetables, and supplements (vitamins, minerals, and other).1

To date there have been no quality, rigorous clinical trials evaluating the effectiveness of the program for weight loss or disease prevention or the safety of the program in people with diabetes.1 The initial registration fee is at least $400 (half of which is reimbursed if you keep within 5 lbs of your goal weight for 1 year) and the weekly cost of pre-packaged meals is at least $100. A US News and World Report Expert Panel gave the Jenny Craig diet 3 out of 5 stars for effectiveness in people with diabetes.2

Weight Watchers

Founded in the 1960s, Weight Watchers offers a range of different weight loss programs and other related tools. Weight Watchers diets generally consist of balanced, low-fat, low-calorie diets, tailored to the needs and preferences of individuals. Programs involve weekly meetings (there is a fee to attend). Eating plans use the strategy of assigning points to different foods (carbohydrates, fats, protein, fiber) based on calorie content and how easily the nutrient is to burn off, with participants adding up points of food consumed during the day with the goal of staying under their daily target. The number of points roughly correlates to total calories. However, foods like fruits and vegetables, which are easier to burn off, have a zero point value. One strength of the Weight Watchers program is the community support mechanism built into weekly meetings. The program also offers a range of online tools. There have been few rigorous long-term studies of Weight Watchers evaluating the effectiveness in weight loss and there are no rigorous studies of the program in people with diabetes.3,4

The cost of Weight Watchers varies depending on the specific program. A monthly pass for participation in weekly meetings is approximately $40 (this includes access to online eTools). There is a one-time registration fee of $20, which allows you to attend weekly meetings on a pay-as-you-go basis (per-meeting cost: $12-$15). A 3-month subscription to the online plan only costs $65. None of these fees include Weight Watchers food products, which are available a grocery stores. A US News and World Report Expert Panel gave the Weight Watchers 3 out of 5 stars for effectiveness in people with diabetes.4

Atkins Diet

The Atkins Diet represents a departure from the USDA Food Pyramid, in which carbohydrates figure as a dietary staple. Instead, the Atkins diet advocates limiting carbohydrate consumption and increasing consumption of protein and fats (eggs, meat) as a primary source of energy. The diet is based on the premise that consumption of carbohydrates (such as pasta, bread, potatoes, and cereal) stimulates production of high amounts of insulin, which causes fat storage and weight gain. The diet limits carbohydrate consumption to 20 grams per day (12 to 15 grams from vegetables that are high in fiber). The long-term effectiveness and safety of the Atkins diet (and similar diets) has been a subject of debate among experts. Many experts have found that the diet leads to increased health risks, including risk for type 2 diabetes and kidney disease.5,6

Although the Atkins diet has resulted in short-term weight loss in studies, its effectiveness as a long-term dietary approach to obesity remains to be determined. Low-carbohydrate diets, such as the Atkins Diet, are not recommended by the American Diabetes Association, with safety concerns including the potential for nutritional deficiencies related to increased protein and fat consumption.7 A US News and World Report Expert Panel gave the Atkins Diet somewhat over 2 out of 5 stars for effectiveness in people with diabetes.6

Paleo (caveman) diet

The paleo or caveman diet is based on what we know about the eating pattern of paleolithic humans who lived 10,000 years ago, before the emergence of agriculture. This diet consisted of wild meat, fish, insects, eggs, fruit, berries, vegetables, and nuts. Food groups including seeds, beans, refined fat, sugar, oil, potatoes, grains, and dairy products were rarely consumed. The modern Paleo or Caveman diet is based on this eating pattern, keeping carbohydrate consumption low (about 23% of total calories) and fat high (about 39% of total calories). Proponents of the diet claim that anthropologic evidence shows low rates of chronic diseases, such as diabetes and heart disease, during the paleolithic era and claim that the prevalence of these illnesses during the modern era are due to the consumption of foods for which as a species we were never fully adapted to consume. There is currently a lack of evidence concerning the benefit of this diet in terms of weight loss or prevention or treatment of any disease, including diabetes. A US News and World Report Expert Panel gave the Paleo diet 2 out of 5 stars for effectiveness in people with diabetes.8,9

Very low-calorie diets

Diets consisting of total calorie intake of 200-800 calories per day are considered very low-calorie diets. Those with a total daily calorie intake below 200 calories are referred to as “starvation diets.” These diets are based on the principle that very low-calorie intake forces the body to draw on fat stores, resulting in rapid weight loss. In terms of long-term weight loss, very low-calorie diets have not been shown to be more effective than conventional diets. Although very low-calorie diets can result in rapid improvement in high blood glucose and there is evidence that at diet with a daily calorie intake of 600 calories may reverse type 2 diabetes in individuals who are not dependent on insulin, there is currently not enough evidence to determine how effective such as diet is in long-term weight loss or as a treatment for diabetes. Generally, very low-calorie diets should be reserved for individuals who have a specific goal for weight loss, such as preparation for surgery.7,9 Remember always talk to your doctor or your dietitian or nutritionist before beginning any diet to make sure that the diet you choose is safe and effective in helping you achieve your weigh loss goals.

Ornish diet

The Ornish diet was developed by Dean Ornish, MD, who has a long history of directing clinical research in the use of lifestyle modification in reversing heart disease. The diet promotes a low-fat, vegetarian pattern of eating, with fat comprising under 10% of total daily calories (15-25 grams per day), carbohydrates comprising up to 75% of total daily calories, and protein comprising 15% to 20% of total daily calories. The diet stresses the importance of eating carbohydrate-rich foods such as beans, vegetables, fruits, and whole grains, and limiting consumption of processed foods, sugar, alcohol, and high-fat dairy products. To help the individual maximize the right foods, the diet places foods into 5 categories based on how healthful they are. In addition to advocating a pattern of eating, the diet also encourage regular aerobic exercise and a stress reduction program, including mediation. The Ornish diet has been shown to be highly effective in reducing the risk of heart disease and reducing both high blood pressure and high blood cholesterol. While the diet may be a successful way of losing weight and improving cardiovascular risk, it may be difficult to adhere to because it represents a fundamental change in eating patterns for most people. A US News and World Report Expert Panel gave the Ornish diet 3+ out of 5 stars for effectiveness in people with diabetes.10,11

DASH diet

The Dietary Approaches to Stop Hypertension (DASH) diet, is a diet designed by the US National Heart, Lung, and Blood Institute (NHLBI), based on the USDA updated Food Pyramid, for the purpose of reducing blood pressure. The DASH diet promotes increased consumption of vegetables, fruits, and low-fat dairy products while limiting consumption of total fat, saturated fat, cholesterol, and sodium. The diet also limits consumption of sugar, including sweets and non-diet sodas. The diet has been shown to be effective in reducing blood pressure. A variety of DASH diet tools are available (some for free from the NHLBI—see below for website address) to assist individuals in selecting foods and determining how much of selected foods should be eaten. The DASH diet has been widely studied and is approved by a majority of health experts. Although there are only a few studies specifically showing its benefits in people with diabetes, the diet generally reflects the dietary advice recommended by the American Diabetes Association (ADA). It is the top rated weight-loss diet by US News and World Report Expert Panel, which also rated the diet 3+ out of 5 stars for effectiveness in people with diabetes.12,13

Vegetarianism

Vegetarianism is a dietary practice based on consumption of only vegetables, fruit, nuts, and grains. According to the American Dietetic Association, a well-planned vegetarian diet can provide required nutritional intake. Vegetarian diets are associated with reduced risk for obesity and may be effective as a dietary weight-loss approach. Additionally, there is evidence that a vegetarian diet can reduce risk of developing type 2 diabetes.14,15

Veganism

Vegan diets are vegetarian diets that also eliminate other types of animal products, including eggs, milk, and cheese (sometimes honey, as well). There is recent evidence
that a low-fat, vegan diet may decrease risk for heart disease among people with diabetes more successfully than the general diet recommended by the ADA.14,16

Written by: Jonathan Simmons | Last reviewed: May 2014.
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