Alcohol's Effect On Metabolism
Alcohol provides empty calories. No nutritional benefit is derived from alcohol. Alcohol is 7 calories per gram which is almost as high as fat in caloric content. In addition alcohol temporarily slows down the metabolism. The effect of this is that less fat is burned (lower BMR). Generally, high fat foods are consumed with alcohol which makes matters worse. Also, alcohol inhibits the liver from metabolizing fat. As you can see any weight loss programs has to exclude alcohol.
Caffeine's Effect On Metabolism
Caffeine increases the mobilization of free fatty acids in the blood which are used for prolonged energy requirements as in marathon running. Caffeine has also been shown to decrease fatigue during low to moderate intensity exercise lasting over 2 hours. However, caffeine is a central nervous system and cardiovascular stimulant thereby increasing the basal metabolic rate, heart rate and blood pressure. Rapid heart rate can occur leading to an unusually high heart rate during exercise. However, after approximately 45 minutes from caffeine ingestion, Bradycardia occurs, or a slowing of the heart rate, and lasts for up to an hour thereby decreasing cardiac output. Bradycardia leads to fatigue and an inability to exercise. Long term effects decrease as the body adjusts to the caffeine intake level. Caffeine is a diuretic and therefore may promote dehydration due to increased urination. Any level of dehydration can decrease energy levels up to 30%.
Anorexia Nervosa is characterized by starvation. Bulimia Nervosa is characterized by gorging and then purging by vomiting or ingestion of laxatives. Both disorders have psychological roots and require professional help. In each case the body losses valuable nutrients. The body will then catabolize muscle tissue to provide the nutrients for the basic life functions even to the point of consuming the heart muscle for nutrients resulting in death.
Popular Fad Diets
There are many popular fad diets available. Each one is heavily promoted to achieve the same goal weight loss. Many are unfounded are some are promoted by people without nutrition credentials.