The Atkins Diet
What is it?: A diet based on the idea that Carbohydrates are the cause of excess body fat, and that limiting or cutting them out of the diet will lead to weight loss. Since Carbohydrates are the body’s preferred source of energy, if they are not present, the body will start breaking down fat for fuel, which will cause the body to burn fat more efficiently. Carbohydrates are limited to 20 grams for the first two weeks, and then gradually increased until desired weight is achieved
Claims: Quick weight loss with no feelings of hunger as well as better heart health, memory and overall wellness
Acceptable foods: There is no limit on foods that contain protein and fat, such as meat, eggs, cheese and non-starchy vegetables but consumption of carbohydrates are limited or cut out completely
What’s is really going on?: When carbohydrates are not available to fuel the body, your body will start breaking down fat stores and releasing fatty acids into the blood. High amounts of these fatty acids will cause “ketosis”, which will make you feel less hungry. While weight can be lost rapidly, the majority of weight lost in the early stages of this diet is water weight. When the body is metabolizing carbohydrates, it produces water as a by-product. Therefore, no carbs means no extra water is being produced. Additionally, think about the carbohydrate sources we, as a nation, are consuming in US. Things like large portions of pasta, bagels, muffins, pastries and french fries are not only high in carbohydrates, but they are also high in calories and fat. It is no wonder that following a low-carb diet that cuts foods like this out will lead to weight loss.
What scientific studies say: While weight loss is possible, maintenance is unproven. Carbohydrates are the body’s preferred source of fuel, and are absolutely essential for brain function.
The Dukan Diet
What is it?: A four-phase high-protein, low-calorie diet that does not include weighing food or counting calories. Protein is the focus in all four phases, while small amounts of vegetables, grains and fruits are added back in during later stages.
Claims: Rapid weight loss at a rate of up to a one to two pounds per day during the first stage. Hunger will disappear after the third day of following the diet.
Acceptable foods: Lean protein sources such as beef, turkey, chicken and fish, eggs and non-fat dairy products.
What is really happening?: because of it’s focus on high-protein foods, this diet has similar effects on the body that the Atkins diet does. The diet does not provide a significant amount of carbohydrates and therefore causes the body to go into a state of “ketosis”, and hunger will be minimized. However, unlike the Atkins diet, the Dukan diet emphasizes drastically cutting the number of calories consumed, which will of course lead to weight loss.
What scientific studies say: The strict parameters of the Dukan diet does not allow for dieters to consume all the nutrients, in appropriate amounts, necessary for good health. The elimination of many foods will likely cause dieters to only follow this diet for a limited time, and weight management after stopping the diet is unproven.
What is it?: A diet that uses a person’s blood-type to determine what foods they should be consuming.
Claims: Eating foods that “agree” with your blood-type will reduce risk of heart disease, obesity, diabetes and liver disease. The diet also claims those who follow it will lose weight, have improved digestive function, resistance to stress and overall energy and mental clarity.
Acceptable foods: Individuals that are Type A should be vegetarians and avoid meat and dairy products, while those who are Type B should eat read meat and fish. Type AB Individuals should eat a combination of foods from Type A and B.
What Scientific studies say: While the basic foods recommended in this diet are typically wholesome, natural foods, and include minimal, if any processed foods, there is no support for the idea that dieters with different blood-types have different nutritional needs.
What is it?: HcG, or human chorionic gonadotropin , is a hormone produced by pregnant woman that ensures her growing fetus will receive optimum nutrition, no matter what the mother’s nutritional status is, by using her fat stores (note that this description of HcG is from a HcG diet info website and is not my interpretation of the hormones activity). In the HcG diet, dieters takes HcG three times per day to break down fat stores to be used for energy.
Claims: Rapid weight loss at the rate of multiple pounds per day
Acceptable foods: The HcG diet is very strict, only allowing dieters 500 calories per day from foods such as protein, fruits and vegetables.
What is really going on?: This one is simple. Eating 500 calories a day would cause a 95 year-old bed ridden woman (who obviously has very low energy needs) to loose weight at a fast pace. 500 calories a day is not enough for anyone, and will most certainly lead to weight loss at a dangerously rapid weight. The only thing that HcG will make thinner is your wallet because whatever form dieters choose to take it in (injects or orally) is extremely expensive.
What science says: There is no proof that HcG promotes weight loss in any way. Severely limiting calorie and food consumption could potentially cause essential nutrient deficiencies.
Long story short, all of these diets require dieters to go to extreme measures that might lead to temporary weight loss, but the evidence that they work long term is questionable at best. The equation is simple, to loose weight you must expend more calories that you consume on a daily basis. The key to lasting weight loss is behavioral modification and lasting lifestyle changes. Healthy weight loss diets should:
-Provide enough energy (about 1200 kcals a day for women and 1600 kcals a day for men) to prevent the body from going into “starvation mode”, which will only cause metabolic process to slow down
-Should not cut out whole food groups or certain foods
-Should provide adequate amounts of macro and micro-nutrients
-Should result in a weight loss of no more than 1-2 pounds per week