Minimal Caloric Intake Diets

The U.S. Department of Health & Human Services Office of the Surgeon General states that nearly two out of every three Americans are either overweight or obese, and one out of every eight deaths in the United States is linked to complications due to obesity. Excess body fat accumulates when a person consumes more calories per day than are expended through physical activity. The Centers for Disease Control states that a person may lose weight by consuming fewer calories than his body uses for energy, which is known as a minimal caloric intake diet.

Theory

The notion behind minimal caloric intake diets is to reduce the total number of calories consumed in a single day while increasing activity level. Upon doing so, the body must call upon stored fat cells for energy. As these fat cells are depleted, they become smaller, thus causing the body to loose weight. The goal in a minimal caloric intake diet is to provide the body with ample calories to sustain energy and health while simultaneously engaging stored fat cells for energy. The Harvard School of Public Health simplifies the method of caloric intake: weight change is equal to the number of calories consumed versus the number of calories burned in a 24-hour period.

Gender Differences

While men and women both lose weight by expending more calories than they consume, the amount of calories a man requires to maintain a healthy body differs when compared to a woman. For example, the Harvard Medical School Family Health Guide states that a 125-pound woman with a moderate activity level requires 2,000 calories a day to sustain her body; a 175-pound male with the same activity level requires 2,800 calories per day. Since a male's muscle-to-fat ratio is higher than a female's, men require more calories to sustain their bodies.

While the number of calories men and women must consume varies, the equation for losing weight is the same. The Mayo Clinic states that 3,500 calories are equal to one pound of body fat. Thus, to lose one pound of fat you must burn 3,500 calories more than you take in. This may be done by reducing your caloric intake by 500 calories per day, and when you multiply this by seven days you will lose one pound of body fat per week just through reducing your daily caloric intake. Your total minimum caloric intake will vary not only according to your gender, but also your age, activity level and current body size.

Physical Activity

Your physical activity level directly affects the minimum number of calories you must consume on a daily basis. For example, people with a sedentary lifestyle, which is a person who engages in light physical activity, will not need to consume the same number of calories as a person who engages in a highly active lifestyle. To determine your caloric intake based on your physical activity level, use the University of Arizona Resting Energy Expenditure, REE, and Total Energy Expenditure, TEE, formula. To determine your REE, a man should multiply his body weight by 11, and a woman should multiply her body weight by 10. The resulting number is the minimum number of calories one should eat to lose body fat. For example, a 175 pound man's REE is 1,925 while a 135 pound woman's REE is 1,350. To determine your TEE, you multiply your REE number by your Activity Factor. The activity factor ranges from 1.0 to 2.4 for men or 2.2 for women. The resulting number is the maximum number of calories per day to maintain your weight.

Warnings

It is vital to consult with your physician prior to reducing your daily caloric intake. By consuming too few calories you may lose body weight, but this reduction may cause severe side effects. The Weight-Control Information Network of the National Institute of Diabetes and Digestive and Kidney Diseases reports those undergoing a minimal caloric intake diet, known as a very low-calorie diet, may experience side effects such as diarrhea, fatigue, nausea or constipation. Other, more serious, side effects may include gallstones, increased cholesterol levels and the inability for the gallbladder to expel and contract bile. Those who use minimal caloric intake diets are also more susceptible to weight gain once the diet is concluded.