Factors Influencing Food Consumption

Several factors may influence food consumption and thereby the total nutrient in take of any individual. These factors range from appetite loss, which may result from conditions as varied as transitional depression to consumption of certain drugs; micronutrient deficiency or toxicity, which may alter appetite through the impact it has on taste sensitivity; dieting, which purposefully lowers total food consumption with the hope of achieving a desirable weight loss; and overtraining, which is a major problem for many athletes.

Appetite Loss A loss of appetite (anorexia), regardless of the cause, interferes with food consumption and may result in malnutrition if it progresses for a sufficient duration of time. Appetite can be affected by both nutrition and non-nutrition factors. A death in the family, for instance, often leads to some reduction in appetite, while a zinc deficiency is also associated with appetite loss. Inadequate consumption of carbohydrates, as is possible on high-protein, high-fat, low-carbohydrate diets, may result in some degree of ketosis, which is associated with nausea and a loss of appetite. Consumption of certain drugs is also known to result in an altered taste perception or an appetite loss, both of which may result in lower energy consumption. Even something as seemingly unimportant as a small toothache can reduce food intake or, at the very least, reduce the variety of foods consumed so as to create a below-optimal nutrient and energy intake.

Micronutrient Deficiency or Toxicity Micronutrients also play a role in appetite, creating a problem that is difficult to address. A deficiency of a vitamin, thiamin for instance, results in poor appetite. However, because this deficiency creates poor appetite, it becomes difficult to increase food intake to reverse the deficiency. See table for a list of vitamins and minerals that may create a loss of appetite from either an Tylenol with codeine Amphetamines excessive or deficient intake.

Popular Diets Popular diets are, by design, meant to restrict the intake of foods. Some diets achieve this by eliminating whole food groups, while others encourage the intake of some energy substrates (typically protein and fat) while discouraging the intake of other substrates (typically carbohydrate). Regardless of the diet plan, most diets involve a massive reduction in calories that ultimately results in a loss of lean mass and a reduction in performance. Sudden and large reductions in caloric intake result in a lowering of fat-free mass (i.e., lean mass), which results in a lowering of metabolic rate. This condition forces people to constantly eat less to adapt to the frequent ratcheting down of metabolic rate. At some point, low-calorie diets become low-nutrient diets, with all of the potential dangers associated with a chronically inadequate nutrient intake.

Overtraining Overtraining can lead to a cascade of problems including sleep loss, increased illness frequency, and appetite loss. The major point to remember here is this: Anything that interferes with food intake is likely to have a major impact on nutrition status and energy intake, both of which will diminish athletic performance and will likely place the athlete at increased disease risk. Athletes who experience sleepless nights, constant fatigue, frequent illness, appetite loss, weight loss, and large mood swings are likely to be overtraining.