I will be comparing three popular fat loss programs, Atkin's Diet, Fit for Life Diet and Weight Watchers. Let's look into the Atkins Diet first. The Atkin's Diet is a low carbohydrate diet that has four phases. Each phase you add a little more grams of carbohydrates to your diet. By the time you hit the last phase which is phase four you are only consuming 70 plus grams of carbohydrates. When your body is this low in carbohydrates it starts using fat as its primary source of energy instead of carbohydrates and if your carbohydrates stay to low for to long your body will take the energy it needs not only from your fat but your muscles as well. You will lose weight with this diet but the bad out weighs the good. We need carbohydrates for our, brain, heart, muscles and other vital organs. Our body uses carbohydrates as the primary source of energy; you will be tired, grumpy and in my case when I tried this a long time ago, craving sweet foods. This diet could not support intense training because of the low carbohydrates. A healthy diet would be one that has the proper blend of protein, fats and carbohydrates for the individual. Now let's look at The Fit for Life Diet. This diet states that weight is gained by eating protein rich foods at the same time you eat foods that are rich in carbohydrates. It argues that the enzymes that breakdown protein interfere with the enzymes that breakdown carbohydrates, and therefore should not be eaten together. With these low protein diets you will experience muscle soreness and fatigue. Our body is replacing old cells everyday. Every six weeks the cells in our liver are replaced. Each month our body produces a full set of new skin and so many other important functions take place. All of the cells that our body replaces come from the protein we consume each day. So this low protein diet is not recommended period. The final fat loss program is the Weight Watchers program. Here is the scientific approach to weight watchers, this information was taken from their website, http://www.weightwatchers.com There are four principles from which Weight Watchers will not waiver. First, any approach developed by Weight Watchers must provide healthy weight loss, which means: Produce a rate of weight loss of up to two pounds per week (after the first 3 weeks, during which losses may be greater due to water loss). Guide food choices that not only reduce calories, but meet current scientific recommendations for nutritional completeness and reduced disease risk. Construct an activity plan that provides the full range of weight- and health-related benefits that exercise offers. Be sustainable. Healthy weight loss is weight loss that lasts, so it is necessary to look beyond losing the excess weight and address keeping it off. This program is not a low carb, low fat or low protein diet. From the information I have gathered on this program, I believe it offers a healthy routine of eating and can stand up to intense training. This program takes into account a food's protein, carbs, fat, and fiber.