With so many different diets available, how are we to know what works and what is safe? The only way to be sure is to discover author's background and research behind diet's methodology. Every good diet should give a background about author and his/her credentials and experience in fields of nutrition and biochemistry. However, even a vast resume does not mean a credible and safe diet. But it does suggest, at least, that author has some knowledge of nutrition. Providing research behind diet proves that diet is not something author invented, so long as research is not self-serving and altered to fit a hypothesis.

Some diets may not need a great deal of tests and studies behind them, simply because they are based on fundamentals. For example, many women's magazines have articles on dieting and weight loss, but they are common sense suggestions that most people concerned about weight should know already: "Eat smaller meals", "cut down on sugar and fat", etc., are typical philosophies. More structured diets should give some scientific reasons for its suggested success, preferably case studies and research performed on everyday test subjects, as well as athletes.

Since we have established importance of eating a balanced diet in accordance to selecting healthy foods and obtaining RDA minimums, it is possible now to rate diets in accordance to those specific criteria. Begin with a score of 200 and subtract 10 points from total for each statement below in which diet concedes. An ideal diet should maintain a score of 200, but a score of 160 or greater is acceptable.

1. The diet does not include food groups in adequate amounts. Some fad diets eliminate one or more of food groups. Do not deduct 10 points if a food group’s nutrients (e.g., carbs, proteins, fats, fiber, vitamins, and minerals) are adequately substituted with that of another food group.

2. The diet does not provide at least 45% of its calories from carbohydrate sources. In order to prevent ketosis, at least 150g of glucose/day is required. That’s 33-50% of total calorie intake on a 1200-calorie diet. Keep in mind that is minimum. For highly active individuals, that amount should increase to 60% at times, i.e., immediately after exercise.

3. The carbohydrate content exceeds 20% concentrated sugars. At least 80% of carbohydrate sources should be complex, and preferably in form of vegetables, seeds, and legumes.

4. The protein content exceeds 30%. A very high protein intake is unnecessary, it places additional strain on urinary system, and it is a poor source of energy. Thirty percent is more than adequate, even for growing children and teenagers. The only group that requires higher protein intake are those who recently suffered a severe injury (e.g., leg amputation), infection, or surgery. However, these individuals will be under care of a physician with a special high protein diet.

5. Protein content accounts for 15% or less of total calories. Although unnecessary in large amounts, protein still has many vital functions, including tissue repair and formation of enzymes.

6. Fats exceed 30% of total intake. Besides increasing risk of cardiovascular disease, high fat diets have not been demonstrated to decrease weight better than other methods of ‘proper’ eating.

7. Total fat consumption is less than 15% of total calories. Fat in moderate amounts is essential for a healthy diet, and such a diet provides taste to many foods. Fat intake below 15% for long periods, for most individuals, is unrealistic. Fat intake that is too low can also be detrimental to children and teenagers who require ample kcalories for continued growth.

8. Total fat consumption is less than 25% essential fatty acids, and saturated fat is more than 30% of total fat consumption. Deduct 10 for each.

9. The diet does not suggest common foods, meaning foods you should be able to obtain at any grocery store or market.

10. The foods for diet are expensive or monotonous. Some diets require purchase of ‘their’ foods or expensive ‘organic’ foods only obtained through health food stores. Some foods taste so bad they are difficult to tolerate repeatedly (e.g., seaweed). Deduct 10 for each.

11. The diet consists of an inflexible meal plan. The diet does not allow for substitutions or deviations, requiring a person to live under ‘house arrest’ with same food selections every day.

12. The diet provides less than 1200 kcalories per day. Less than that and body's basic functions may not be getting energy, vitamins and minerals needed to work properly, and dieter almost is certain to feel hungry all time. Diets below 1200 kcalories should be reserved for those under supervision of a dietitian or licensed physician. 13. The diet requires use of supplements. If diet provides adequate energy and it is well balanced, supplements are unnecessary. ‘Fat accelerators,’ such as ephedrine, may increase rate of weight loss, but diet should be able to stand on its own merit. Some diet clinics promote a vast array of herbal preparations and fat accelerators, and this is where these clinics make their money – not in their knowledge and ability as nutritionists.

14. The diet does not recommend a realistic weight goal. Diets should not be promoting body of a Greek god or a supermodel. They should not be suggesting that a person lose 100 pounds (even if 100 pounds overweight). Nor should diets recommend weight loss below an ideal weight.

15. The diet recommends or promotes more than 1-2 lbs/week weight loss. Do not expect to lose more than 1-2 pounds of fat a week – it is physically impossible unless chronically obese, at which point 3 pounds may be possible. If more than two pounds is lost per week, body change is due to a loss of water and/or muscle tissue. Gimmicks that promise 10 pounds in 2 weeks are either simply not true or else something other than fat is being lost. Also keep in mind that more fat a person wishes to lose, and less a person has, more difficult and slower it will be to lose additional fat.

16. The diet does not include an evaluation of food habits. Dieting should be a slow process by which a person changes normal eating habits. It should not include looking for quick fixes and quick plans promising short cuts and extreme changes – a person would never stay with these programs and such diets do not work long-term. The number of kcalories eaten, and food selections and their amounts, should be reevaluated on a regular basis… perhaps once every 1-2 months to determine program’s effectiveness.

17. Regular exercise is not recommended as part of plan for proper weight loss. Weight loss occurs twice as fast with exercise, and without exercise there is a greater tendency to lose lean muscle tissue as well as fat. This is not ideal.

OVERVIEW OF VARIOUS DIETS

The South Beach diet is always confused with Atkins Diet, which is a low-carbohydrate diet. The South Beach diet highlights consumption of “good carbohydrates” (high in fiber) and low in glycemic index. The South Beach diet was developed for patients with heart problems to lose weight without risking ketosis. The weight loss was a side effect which turned out to be beneficial and this encouraged many people to try South Beach diet.

According to South Beach diet theory, highly processed carbohydrates are quickly digested which makes insulin level to shoot up. Once carbohydrates are all used up, your high insulin level makes you crave more for carb-filled foods.

The South Beach diet is based on observation that Americans are carb crazy, which is also reason for induction phase. In first two weeks, dieters attempt to eliminate bad carb such as grains or fruits. After this phase, grain-based foods and fruits are returned to diet with concentration on foods with low glycemic index.

The South Beach diet also emphasizes difference between good and bad carbohydrates, and good and bad fats. Good carbohydrates have low glycemic index which means that they are slowly digested and absorbed. The South Beach diet bans unhealthy fats such as saturated fat.