Weight loss and the strategies advertised as achieving weight loss are a remarkable example of human nature at its most capricious. It seems that a large percentage of the adult population of modern Western culture is prepared to seek and pursue a weight loss solution, in the midst of societies where fast foods rich in saturated fats, sugared beverages, and generally unhealthy physical habits reign supreme.
The advertising campaigns in support of commercially advocated weight loss schemes that regularly appear in North America appeal primarily to the vanity of the individual. The scientific imperatives behind weight loss are far starker and far more compelling than if one looks attractive. Excess body weight impacts human performance in a multitude of ways, all of which are serious. There has been a flood of statistical data in recent years to support various campaigns aimed at addressing the lack of fitness people of all ages. Governmental and private organizations throughout the world have highlighted the rise in the incidence of overweight and obese children, and the predicted crippling public cost of the additional health care that will be necessitated by the consequences of obesity in adults.
Weight loss strategies are compelling in the face of this data. Aircraft, movie theater, and sports stadium seating is now too narrow to accommodate the typical modern North American adult. The incidence of diabetes, osteoarthritis, cardiovascular illnesses (including high cholesterol), coupled with the doubling of rates of adult and juvenile obesity (generally defined as when the percentage of body fat in a given individual exceeds 30%), have lead researchers to conclude that the present generation of young people (those born after 1985) may be the first generation in recorded history to experience a shorter lifespan than that of their parents.
The Office of the Surgeon General of the United States estimated in 2006 that 300,000 Americans die every year as a result of complications stemming from obesity, with childhood obesity increasing 230% since 1980. It is further estimated that 62% of all Americans are overweight.
From a physiological perspective, weight loss is a simple proposition, and the negative health consequences of excess body weight are consequently significantly reduced. The body has two basic structural components when assessing the ideal weight for any individual. Lean body mass is the weight of the body's skeleton, organs, and muscle. Body fat is the product of the food consumed through diet that is not immediately required by the body for energy. Stored as triglycerides in the specialized fat storage cells known as adipose tissue, body fat plays an important role as a reserve energy source, as well as insulation for the more vulnerable internal organs. While excess body fat is an unhealthy physical state, small percentages of body fat are desirable; healthy males, depending on their age, physical build, and the nature of sports activities, will possess a body fat percentage of between 10% and 15%, while females naturally possess greater amounts of body fat, and a healthy woman may possess between 16% and 20%.
One pound of body fat represents stored energy in the body of 3,500 calories. To lose weight at a rate of 1.5 lb per week (a figure often cited as a safe rate of weight loss), the person must either reduce food consumption or increase the level of physical activity by a total of 750 calories per day (5,250 ÷ 7).
The weight loss issues faced by athletes are not generally as dramatic as those for members of the general population. Most athletes who perceive a need to reduce their weight have a specific athletic objective that is measurable, such as being able to finish a training run, or lift a specific amount of weight. When the athlete is actively engaged in a sport, but seeks to reach a perceived ideal weight for competitive purposes, the formulation of a weight loss plan must include the following components: targeted ideal weight; current weight; and level of fitness, including body fat and lean muscle mass, physical conditioning factors (such as preexisting health concerns), and the anticipated competitive schedule.
For active athletes seeking to achieve a reduction in their current weight to a desired weight, rapid reductions in weight are usually not healthy nor do they enhance their present athletic ability. To maintain a minimum level of fitness, the athletes must continue to train at their current level, or even harder during an active period of weight loss. Training requires careful attention to the athletes' nutritional needs, and a reduction in food intake. Additionally, increased training creates a risk of nutritional deficits. Using the calculation of the energy contained in one pound of body fat, an athlete could continue with a normal diet (subject to an analysis of the nutritional issues that may have lead to the weight gain), and lose weight through increased training alone.
The multitude of commercial diets, particularly those that promote low carbohydrate intake, must be approached with considerable caution by an athlete seeking to lose weight. In a typical balanced diet, the body will receive 60-65% of its energy sources in the form of carbohydrates, 12-15% as proteins, and less than 30% as fats. Carbohydrates are the preferred energy source for many types of human functions, including those of the brain and the nervous system. Purported low-carbohydrate diets proceed on the proposition that when the body has limited carbohydrates available, it will naturally turn to its fat stores as an alternative. If the only concern were the accessing of fats, this diet might operate as intended. However, athletes and the energy pathways (anaerobic, anaerobic alactic, and aerobic) used by the body to power muscular function only operate optimally when the energy stores are compatible.
A further difficulty for the athlete on the low-carbohydrate diet is the fact that many micronutrients (including all vitamins and most minerals) and phytochemicals tend to be most prolific and readily absorbed into the body through carbohydrates such as fruits and vegetables. Weight loss without a corresponding maintenance of nutritional health is an undesirable state of any athlete.
There are a number of specific weight loss scenarios that carry significant psychological issues. Eating disorders are prevalent among young females, a demographic where concerns over body image are often a motivation to extreme diets. Among female athletes, the sports of gymnastics, diving, and figure skating emphasize physical presentation and appearance, to the extent where, in some circumstances, the athletes will convince themselves that their body is inadequate for competition. The mental illnesses of bulimia and anorexia nervosa are the best known of these disorders. Bulimia is a condition where the athlete will commonly eat and purge, apparently consuming regular quantities of food, but eliminating meals through either vomiting or the use of laxatives. Anorexia nervosa is a self-imposed starvation to achieve thinness; anorexia can be fatal.
Weight loss supplements, fat burners, and so-called diet pills are sometimes touted as fast-acting remedies to assist in the elimination of excess weight. As with many of the products sold commercially as weight loss supplements, there are nuggets of factual science-based material buried among the claims of speedy, effortless weight loss. The first of the common and truthful representations made is that the determination of the basal metabolic rate (BMR) for every individual is important in the development of a weight loss strategy. The BMR is an expression of how much energy an individual consumes in a given day. The BMR will fall within a range for all persons, generally in relation to their body type. There are three generally recognized body types: the ectomorph (thin, smaller bones build), the endomorph (the rounder, stouter build), and the mesomorph (larger, more muscular build).
Many of the fat burner supplements have thermogenic qualities, meaning that they will increase the BMR of an individual to a limited degree by increasing the energy generated by the body and stimulate the metabolism. As with any nutritional supplement, knowing exactly what is contained in the formulation will indicate whether the product will promote or assist in weight loss in a safe manner. A number of weight loss products include known stimulants such as ephedra or ma huang (containing ephedrine), caffeine (including herbs such as guarana), bitter orange, and similar substances. Stimulants tend to act as an appetite suppressant through their action
There is little question from a scientific standpoint that the best weight loss programs are those that simply combine exercise and a reduction of calories in diet, without compromising nutrition.