Starvation diets – why they won’t work
I read this today on the Guardian Food and Fitness website and thought it might be appropriate to this community (although please feel free to remove if it's not). :-) The full article can be found here:http://www.guardianeatright.co.uk/news/article.cfm?code=27051&article_id=1699
I've just quoted the salient points from it below. All italics are mine:1. Fasting results in rapid initial weight loss
Under normal circumstances, the principle fuel for the body is glucose. The brain, in particular, must receive a constant supply of glucose in order to function properly. During a period of calorie restriction, glucose, which is stored in the liver as glycogen, is used first to supply energy.
Glycogen is stored with water, so when it is broken down for energy, water will be released as well. It is this fluid that is responsible for the rapid weight loss that occurs in the first one to two days (anywhere between three to five pounds per day) of severely calorie-restricted diets,
such as the Hollywood Miracle Diet, Cabbage Soup Diet and The Grapefruit Diet, all of which claim that you can lose 10 pounds in two days.
Consequences: If it sounds too good to be true, it is: this weight loss won’t last. When normal eating is resumed, glucose and water stores will be replenished and the original body weight will be attained. The rapid loss of fluid can also lead to the loss of electrolytes and dehydration, so the only things that are "cleansed" from the body are the minerals needed for muscle contractions, nerve transmissions, regulation of body fluids and other physiological functions.
The sudden drop in sugar in the blood, as glycogen stores are diminished, will result in tiredness, confusion and mood swings. These are the symptoms that are often mistakenly thought to be the first step in the cleansing process of a detox diet. 2. Cutting calories slows down weight loss
The liver stores only enough glycogen (energy) to last for one day, so when fasting lasts longer than 24 hours, the body will then turn to muscle to produce glucose for energy.
After following a very low calorie diet or fast for one week, 30 percent of the total weight loss is muscle and the rest is fluid.
The amount of muscle in the body sets your metabolic rate (the rate at which you burn calories). So, as muscle is lost, they perform less metabolic work, saving calories and hence energy. In short, your rate of weight loss will slow down. In fact, most two- to three-day crash diets that claim to burn fat only burn away metabolically active muscle tissue and actually hinder long-term weight loss.
The same applies when skipping meals. When you eat a meal, overall metabolism is increased due to the energy required for digestion and absorption of the meal. Skipping a meal will have the reverse effect, decreasing the metabolism, which lasts until you eat something.
Overall, the body will then save - rather than burn - calories to ensure it has adequate energy during the times of fasting. So, meal skipping to avoid unwanted calories is a counterproductive method for sustained weight loss.
Consequences: When calorie levels are increased to a normal level, weight gain will be faster and the weight will come back as fat,
since your metabolic rate has slowed, and you may even end up heavier than before you began dieting! The loss of muscle will have an effect on your ability to maintain weight loss in the long term, unless muscle is regained by exercising.* 3. Fasting results in fatigue
Body protein provides most of the energy needed during the first few days of a fast, but after that the body will adapt to using fat for energy in an attempt to preserve muscle.
Fat is then metabolised to ketones, which can be used by the brain for energy. However, prolonged inadequate carbohydrate intake results in the build-up of ketones, which become toxic, resulting in a condition called ketosis.
Consequences: The kidneys and liver become burdened with toxic waste from the breakdown of fat and muscle tissue and the body’s normal functions are disrupted. Ketosis can cause fatigue, constipation, nausea and vomiting. The potential long-term side effects of ketosis include heart disease, bone loss and kidney damage.
In addition, the lack of calories will deprive your body of essential vitamins and minerals so hair, nails and skin will show signs of deterioration. Ironically, if you’re using fasting as a means of detoxifying or cleansing the body, you will actually be achieving the opposite effect.
Fasting and fad diets can be very dangerous for individuals with chronic conditions such as diabetes, coronary heart disease, liver or kidney disease, infection or pregnancy.
*I've actually seen this happen to a work colleague who used the SlimFast diet to attain her target weight. Two years after she finished it she's now significantly heavier than she was before she began the diet and is miserable about it. :-( Current Mood: thoughtful