The Red Flags of Junk Science

• Promise of a quick fix
• List 'good' and 'bad' foods
• Very limited selection of foods to be eaten at specific times
• Promote bizarre quantities of only one food or type of food
• No increased physical activity
• Promise rapid weight loss (more than 2 pounds a week)
• Promote magic or miracle foods that burn fat
• Recommendations based on a single study
• Recommendations based on studies that have not been peer reviewed
• Recommendations made to sell a product
• Claims that the body's metabolism can be tricked into burning more fat or calories

Zone Diet

Premise:
For maximum calorie burn and weight loss, you must stay within the 'healthy zone' and consume 40% carbohydrates, 30% protein, and 30% fat at each meal. Author Barry Sears, Ph.D. claims that most people are insulin resistant and that eating carbohydrates makes them fat. Insulin is a hormone that delivers glucose to the cells. Proponents claim that by eating carbohydrates, our bodies overproduce insulin, and cause too may calories to be stored as fat. In this diet, carbohydrates must be matched with a prescribed amount of protein to keep your 'good' and 'bad' eicosanoids, which control 'all hormonal reactions', in balance. 'Bad' eicosanoids increase insulin production and 'good' eicosanoids moderate hunger.

Truth:
This diet has been strongly disputed by the scientific community. While eicosanoids are involved in blood clotting and in the immune system, no evidence shows that this diet affects their synthesis. Only about 20-25 percent of adults are insulin resistant, and this is usually the result of some other health problem such as obesity. Being overweight causes insulin resistance, not the other way around. Any weight lost on this diet is due to a reduced amount of total calories, not a hormonal change.

Blood Type Diet

Premise:
When you eat foods that 'agree' with your blood type, you reduce your risk of infections, cancer, heart disease, diabetes, and liver failure. The diet says people with type A blood have ancestors who were farmers, so they should be vegetarians. Type Bs have nomad ancestors, and should eat red meat and fish. Type Os are linked to hunters and gatherers and should eat mostly animal protein, but not much carbohydrate. Type ABs should eat a combination of types A and B.

Truth:
This theory has not been scientifically documented. The research referred to in 'Eat Right 4 Your Type' by Peter J. D'Adamo, N.D. was conducted by the author and has not been duplicated.

21 Pounds in 21 Days: The Martha's Vineyard Diet Detox

Premise:
A Detox approach to dieting allows the body to release toxins and excess weight. The diet claims to provide maximum nutrition to help heal the visible and invisible damage to body organs and tissues.

Truth:
The diet is cumbersome to follow and the recommendation for colonic therapy has not been scientifically proven to promote weight loss. In addition recommendations for food combining, as a means of weight loss, has not been shown to have a scientific merit.

Atkins Diet

Premise:
You can eat as many calories from fat and protein as you want as long as very few carbohydrates are consumed.

Truth:
The diet allows you to gradually reintroduce more carbohydrates into the diet, but the amount is still less than what is recommended by nutritionists. The body can't burn fat efficiently without carbohydrates. As a result, the body produces ketones that strain the kidneys. People on this diet often get burned out eating mostly meats and high fat foods and begin to have starch cravings. Eating high-fat foods is also a sure way to increase your risk of developing heart disease or cancer. Common side effects of this diet include constipation, nausea, headache, fatigue, and bad breath. There have also been no long-term studies on the consequences of this diet.

The 4 Day Diet

Premise:
The 4 Day Diet claims to push your body to lose more weight because it varies the types and amounts of foods eaten as well as the kinds of exercise. Continually readjusting to new foods and exercises prevents the body from getting acclimated to any specific eating or exercise plan, which in turn will help to burn more calories and prevent plateaus.

Truth:
There is no scientific support for the theory that varying calorie intake and exercise style will result in weight loss more than steady calorie reduction and increasing physical activity. In fact, according to the National Weight Control Registry, consistent eating and fitness behaviors are characteristic of people who successfully lose weight and keep it off.

The author also frequently refers to the Glycemic Index when discussing the types of foods recommended in the diet, but again, there is no evidence a G.I. diet causes significant weight loss or helps control appetite.

Furthermore, although many healthful foods are recommended throughout the modules, readers are at risk for consuming inadequate amounts of some nutrients. For example, most of the diet plan does not meet the 2005 Dietary Guidelines for Americans daily recommendations for whole grains or low-fat or nonfat dairy.

Finally, none of the meal plans, recipes or snacks includes any calorie or nutrient information. The author may spin this as relief from calorie counting, but long-term weight loss (and good health) generally includes learning what you are putting in your body.

South Beach Diet

Premise:
A three phase diet that takes out "bad fats and bad carbohydrates" in order to avoid intake of sugars and starches that are absorbed too quickly.

Truth:
The plan causes weight loss because the average calorie intake is 1400-1500 calories per day. Phase One is a strict avoidance plan where Phase Two and Three combine more balanced intake. Meal plans and recipes for Phases Two and Three are well balanced and would be helpful for those looking for lifelong eating plans.

Flat Belly Diet

Premise:
The Flat Belly Diet consists of two parts: a four-day anti-bloat jumpstart and the four-week eating plan. The jumpstart is designed to flush out fluid, reduce water retention and relieve digestive problems. Dieters are told to avoid the salt shaker, salt-based seasonings,highly processed foods, excess carbohydrates foods (pasta, bananas, bagels and pretzels), bulky raw foods, gassy foods (legumes, cauliflower, broccoli, Brussels sprouts, cabbage, onion, peppers and citrus fruits), chewing gum, sugar alcohols, fried food, spicy foods, carbonated drinks, alcohol, coffee tea, hot cocoa and acidic fruit juice. Dieters must also drink two liters daily of "sassy water"; a blend of ginger root, cucumber, lemon and mint leaves. The jumpstart meal plan provides 1,200 calories daily and a four-day shopping list and sample menus are provided.

Truth:
Despite having a relatively healthy eating plan, there are components of the book that are indicative of a fad diet, including:

• The jumpstart phase requires dieters to suddenly stop consuming caffeine, which can cause severe headaches as well as other symptoms associated with withdrawal.
• Dieters are led to believe MUFAs are the "silver bullet" for weight loss.
• The book claims to be "grounded in cutting-edge science" but the authors fail to provide any scientific rational for "sassy water."
• Rapid weight loss may result from being on this diet, but most of the weight will be water weight.

Bottom Line:
Based on the Mediterranean style of eating, the diet portion of this book is healthy. For individuals who require a 1,600-calorie plan, this book is great. Those requiring other calorie levels will need to work with their registered dietitian to individualize the meal plan.

Liquid Diets

Premise:

Drink two liquid replacement meals and eat a 'sensible' dinner for a total of about 1,500 calories a day. These beverages are fortified with vitamins and minerals and sometimes fiber.

Truth:
Depriving your body of food causes it to go into starvation mode and slow down your metabolism. Then, it holds on to the few calories that you are providing it. As a result, you become tired and feel weak. Being hungry throughout the day may also cause you to overeat your 'sensible' dinner.