In two words..

Wild with the fats, almost no carbs.

Pros and cons

Quick, visible results. Vegetarian-unfriendly.

Good appetite?

Red meat, bacon, eggs, cheese, butter, nuts.

No-nos

Potatoes, rice, pasta, bread, sweets, alcohol and caffeine.

Philosophy

The stated aims of Atkins are to provide people with a lifetime nutritional philosophy which will (a) restrict their intake of processed and refined carbohydrates, such as sugar-rich food, bread, pasta, cereal, and starchy vegetables, (b) encourage consumption of nutrient-rich unprocessed foods such as animal flesh (meat, fish and poultry) and (c) promote the use of "vita-nutrient" supplements. Indeed, there is a heavy emphasis on nutritional supplements, as there is on exercise and regular testing to monitor levels of Cholesterol, Insulin, Blood Pressure and Triglycerides.

By the numbers

Carbohydrates are restricted to around 20 grams per day in the first 2 weeks. A weekly 5 gramincrement is followed until you establish your Critical Carbohydrate level for Maintenance (the highest number of grams of carbohydrate per day which you can consume without starting to gain the weight back).

Method

Phase 1 Induction: 14 days

Purpose: To induce "Benign Dietary Ketosis", a condition whose presence can be detected by Ketostix, which is present when the body is producing Fat Mobilization Substance", a condition whose presence cannot be so detected. Once Fat Mobilizing Substance is being produced, the body is forced to disgorge and burn up deposited body fat. When this happens, you are quickly losing weight. All fruit and most vegetables are excluded. Carbohydrates are restricted to around 20 grams per day. Unnecessary medications are to be abandoned, and medical assessment tests should be taken for the "before" picture.

Phase 2 Ongoing Weight Loss: To be followed until target weight has been achieved

Purpose: Once production of Fat Mobilizing Substance and weight loss have been triggered by the Induction phase, this phase is designed to allow continuing weight loss, while at the same time making the diet less restrictive and more palatable. This is done by increasing permitted vegetables, and raising carbohydrate levels to around 40g per day (exact figures vary, according to degree of metabolic resistance). This is when you set your own weight goal, and towards the end of this phase you establish your Critical Carbohydrate level for Maintenance (i.e. the highest number of grams of carbohydrate per day which you can consume without starting to gain the weight back).

Phase 3: Pre-Maintenance Diet: Commencing 5-10 pounds away from reaching target weight.

Purpose: To prepare for the last phase. At this point, the diet is changed, using the Critical Carbohydrate Level for Maintenance information gained in Phase 2, so that the final few pounds are lost more slowly than before. "The slower you lose the last 5 pounds, the better". This is achieved by increasing the carbohydrate intake till less than 1 pound of weight per week is being lost. Weight loss is "cruising to a halt".

Phase 4 Maintenance Diet.

Purpose: To maintain Target Weight for life. You are no longer protected by Fat Mobilizing Substance, and this phase exists to protect the newly-successful slimmer from thinking he or she can now eat anything, now that Target weight has been reached. It guards against inadvertent folly and recidivism (re-offending). This is achieved by setting a fairly strict diet that will forever keep off the lost weight. The person is urged to stick to the carbohydrate level they feel happiest on without gaining weight.

In two words..

Balancing the "right" fats and carbs.

Pros and cons

Weight loss, weight loss, and more weight loss. Rules, rules, and more rules.

Good appetite?

Lean cuts of meat, poultry, fish, shellfish, eggs, low-fat or fat-free cheese; a later phase includes most fruits, some breads and pastas and brown rice.

No-nos

Refined grains, sweets, potatoes, fruit juices.

Philosophy

Eating good carbs and good fats spread over 6 meals/snacks a day will balance blood levels of glucose, insulin, cholesterol and other coronary heart disease (CHD) markers. While the author claims that the diet is neither low carb nor low fat, it really is generally a high protein, high fiber, low carb and low animal fat diet. This diet was initially developed to help prediabetic and/or heart disease patients with high levels of (bad) cholesterol and triglycerides as well as glucose levels. Weight loss was a side effect that prompted the writing up of the prescribed diet into the book. Thus, the main thrust of this plan is to keep glucose and insulin levels even, and to lower (bad) cholesterol and triglycerides. Weight loss should follow automatically. This is achieved by completely avoiding refined carbohydrates that are quickly absorbed and high on the glycemic index, and by avoiding man-made trans fatty acids as well as saturated animal fats. Eating eggs, fish, seafood, chicken or turkey breast, lean ham, nearly all vegetables and drinking lots of water is encouraged, as well as moderate amounts of nearly all fruits, nuts, other low fat meats, whole grain bread, pasta and rice, olive or canola oil and a glass of red wine a day. Not allowed are any products containing sugar, fruit juices, potatoes, refined grains (bread, pasta, white rice), regular diary, fatter cuts of beef, poultry and pork, butter, and beer.

By the numbers

Eat 3 meals and 3 snacks a day. Never go hungry. No counting of calories, fats or carbohydrates (restricted in Phase 1). Eat of the allowed until you feel full but not stuffed.

Method

Phase 1 is the strictest and is suggested for the first 2 weeks. It is also suggested to return to phase 1 after cheats. In phase 1, no fruit, alcohol or whole grain carbohydrate is allowed – only fish, eggs, lean meats, limited low fat diary and leafy vegetables are eaten – though no carbohydrates are counted.

In Phase 2, fruit, nuts, whole grain products, red wine if desired are added gradually. It is recommended to add one such product at a time and to see what happens before adding more.

Phase 3 or maintenance has no forbidden foods – it is expected that one follows the principles that were learned in the plan for life in general, but exceptions are allowed.

Typical menu: Breakfast small glass vegetable juice, a vegetable quiche (based on eggs, spinach, onion, other vegetables and low fat cheese). Midmorning snack: celery with low fat cheese Lunch Large vegetable salad with shrimps or chicken breast Snack low fat string cheese, nuts Dinner Salmon with asparagus Dessert/evening snack: low fat ricotta dessert with artificial sweetener and fruit

Because of the hybrid nature between traditional low fat diets and Atkins, South Beach is more acceptable for traditional nutritionists and medical professionals. Without counting calories, fat, or carbs, it may seem generous and somewhat subjective: in phase 2, one is instructed to gradually add new items and watch what happens. Because of the stress on glucose, timing can be important, e.g. fruit is allowed in the evening but not morning.

In two words..

Consume a 40/30/30 percent balance of carbs, protein and fats at every meal.

Pros and cons

Steady weight loss, favored by athletes for building lean muscle mass. Very strict rules.

Good appetite?

Seafood, poultry, lean meats, fruits, most vegetables, nuts.

No-nos

Butter, shortening, fatty meats.

Philosophy

An interesting feature of this diet is that there is no induction phase. Once the desired weight loss has been achieved following the initial ratio of carbs, fats, and protein, the ratio is shifted towards the fats to prevent continued loss. Otherwise, you eat the same from the beginning.

By the numbers

40% carbohydrates, 30% protein, 30% fat

Method

Block method. 1 carb block = 9g carbohydrates, 1 protein block = 7g protein (absolutely no fat), 1 fat block = 3g fat. However, since most meats (even lean cuts) tend to have some fat "hanging around", it is recommended to assume that your protein source already has 1.5g fat. Therefore 1 fat block = 1.5g fat.

Typical menu: An average meal for a woman with average activity levels is a 3 block meal. You would have 3 carb blocks (e.g. 1c green beans [1block] and 1 apple [2blocks), 3 protein blocks (e.g. 3oz. of chicken), and 3 fat blocks (e.g. cook your chicken in 1tsp. of olive oil).