By Nutrition Team
Tuesday, May 23, 2012.
The practice of fasting has been around for centuries. It was traditionally employed as a religious ritual used to exercise self-discipline and heighten spiritual awareness. But recently the practice of abstaining from eating has become a trendy way to obtain fast weight loss results.
While one-day fasts pose no serious threat for healthy adults, longer fasts (more than 24 hours) can have grave results. Whether it’s a "water-only" fast used to detox, skipping meals or surviving on only cabbage soup or grapefruit, the body only recognises one thing - starvation. When you don’t consume enough calories to sustain essential functions (such as keeping the heart beating or the lungs breathing), the body reacts by drawing on its own reserves to provide energy. This puts your body under stress - not rest - and is certainly not the answer to permanent weight loss.
So, before you skip even one meal, feast on a bowl of tasty cabbage soup, or finish that first grapefruit, read about the top three dangers of starvation dieting - and find out what you should be doing to keep your metabolism revved up and burning more calories.
The Fast Track To Dieting Dangers
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.
The TRUE Fast Track To Weight Loss
The safest, most sensible route to achieving long-term weight loss is adopting healthy eating habits, which endure long after the pounds have been lost. You'll also want to keep your metabolism revved up to burn calories rather than save them. This can be achieved by:
Having breakfast. A morning meal kick-starts your metabolism after your body has been deprived of food throughout the night. Skipping breakfast keeps your metabolism running slow and you will save rather than burn any calories you eat later in the day.
Snacking frequently. Eating smaller, frequent meals will keep your metabolism working throughout the day. Snacking also prevents you from becoming too hungry. The hungrier you are, the less control you have over what and how much you eat.
Exercising. Cardio fitness activities (walking, jogging, swimming, cycling, aerobics, dancing) speed up your metabolism for several hours after your workout so additional calories will be burned off long after you stop moving.
Lifting weights. This activity will build and tone muscle which burns up to five times more calories than fat (even when your body is at rest). More muscle means more calories burned and more weight lost over time.
Eating according to your activities. If you do most of your physical activity during the day, make breakfast and lunch larger meals so you have enough energy to get everything done.
Drinking plenty of water. Your metabolism needs water to function properly. Remember, the recommendation is 1-2 litres per day.
NOTE: 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.