Dieting

Dieting is the purposeful restriction of food intake as a means of losing weight, experiencing health benefits,  and/or  avoiding  medical  complications associated with excessive weight. Dieting is typically characterized by restrictive eating, where certain foods are limited or avoided entirely. Most diet plans are based on reducing any of the body’s macronutrients, such as fats, carbohydrates, or proteins, which are vital sources of energy.

What Is Dieting?

Dieting refers to many diverse methods for inducing weight loss, such as controlled eating, fasting, and consuming diet aids. The prevalence of dieting has steadily increased over the past 40 years, since an increasing proportion of the population is overweight. The World Health Organization (WHO) has defined overweight as having a body mass index (BMI) of 25 to 29.9 kg/m2. Obesity is defined as having a BMI greater  than  30  kg/m2.  Reports  estimate  that  61% of adult Americans are either overweight or obese. Furthermore, the detrimental effects of being severely overweight are becoming increasingly clear. Overweight individuals have an increased risk for high blood pressure, cardiovascular disease, stroke, type II diabetes, cancer, and other complications (e.g., sleep apnea, gallbladder disease). Medical complications related to obesity are estimated to cost the United States approximately $99 billion per year. In response to these health concerns and further cultural pressures, the percentage of men and women dieting has increased from 7% and 14% in 1950 to 24% and 40% in 1993, respectively. Not only has there been a marked increase in dieting among adults, but adolescent dieting is on the rise as well. Reports from the United Kingdom estimate that 35% to 60% of girls 11 to 18 years of age are currently dieting.

The Need For Diets

Many of the health risks associated with being overweight can be minimized by reducing 5% to 10% of overall weight. Successful diets can actually increase the body’s metabolism through the consumption of smaller meals with greater frequency throughout the day. For example, instead of adhering to a traditional eating schedule of three meals a day, dieters that adhere to an eating schedule of five to six smaller meals stimulate the body’s metabolism. The body’s metabolism is spurred into action with each food source ingested, as the body must break down the necessary nutrients. Healthy, balanced diets can also increase energy levels by omitting sugary and highly processed foods, which rapidly elevate and then drastically decrease blood glucose levels, affecting mood and energy levels. By consuming foods rich in fiber and proteins, blood glucose and energy levels can be maintained at a steadfast level, omitting drastic spikes in glucose levels. Healthy diet plans incorporate foods high in fiber and protein to help slow down digestion and keep glucose levels from rising or falling too rapidly.

The psychological benefits of a successful diet plan can be just as empowering as the physical benefits. As dieters lose weight and improve their health, wellbeing, and physique, they gain confidence in themselves and experience heightened self-esteem and body satisfaction. Successful dieters report increased life satisfaction and emotional well-being as a result of their weight loss and improved health.

The Importance Of Proper Nutrition

Obtaining proper nutrients is essential for growth, reproduction, and maintenance of good health. Nutrients supplied through food sources provide support for all life activities in the cells of all organisms. Nutrients are labeled as carbohydrates, proteins, fats, vitamins, minerals, and water. Our bodies rely on these nutrients for building and repairing tissue, maintaining heart rate and pulse, and providing sufficient body heat. Without adequate nutrition, the body becomes frail and less apt to fight infection. The brain exhibits delayed reactions, the heart ceases to function properly, and in cases of extreme deprivation, death is possible.

The Dieting Dilemma

The dieter must distinguish between the nutrients essential for proper bodily functioning and excessive calories that are counterproductive to weight loss.

Successful dieters must learn to correctly identify the body’s needs and the satisfaction of these needs. The boundary between hunger and satiation is referred to as the diet boundary. This distinction, the diet boundary, is complicated by the fact that people frequently eat for other reasons than the body’s need for nutrients. For example, people may eat to escape boredom, to cope with stress, or as a means of social interaction. Hence, dieters face a dilemma of maintaining an adequate diet boundary as they are immersed in a social world, surrounded by an array of circumstances and food choices. In the midst of these situations, dieters must determine when to eat, how much to eat, and what types of food are appropriate.

How Diets Work

It is ultimately the amount of calories consumed per day that determines the amount of weight lost or gained. The body burns calories as fuel for basic bodily functions. Weight loss occurs when fewer calories are consumed (e.g., dieting) or when more calories are burned (e.g., physical activity). Creating a caloric deficit of 500 calories per day (e.g., via dieting or physical activity) results in weight loss of approximately 1 pound per week. The optimal amount of weight loss per week is 1 to 2 pounds. Amounts exceeding the optimal amount can cause muscle to be burned rather than fat.

Restraint And Disinhibition

One of the hallmarks of dieting is restrictive food intake. As dieters attempt to lose weight, they limit the types and amounts of foods consumed. These rigid periods of restraint can be physically and psychologically draining, as dieters must change the way they eat. This change often results in dieters neglecting the foods they enjoy for the foods on the diet. As a result of these intense periods of restrictive eating, dieters often exhibit the opposite extreme of restraint: disinhibition or overindulgence. These bouts of overeating, also referred to as disinhibited or binge eating, usually occur when dieters exceed their diet boundary.

There are both physiological and psychological factors that perpetuate this restraint-disinhibition connection. Successful diets yield weight loss, which can cause a state of chronic hunger. When body weight drops below a certain set point, the body attempts to physiologically defend the appropriate weight. Intense hunger pains and chronic hunger ensue to cue the individual that more food is required. Binge eating succeeding restrictive eating can also occur as a result of the reduced amounts of fat in most diets. Because fat causes feelings of satiation and fullness, reduced fat intake may increase hunger.

These physiological responses to dieting are amplified by psychological responses to restrictive food intake. As dieters alter their current eating patterns, feelings of perceived deprivation and preoccupation with food frequently occur. Perceived deprivation is caused by dieters eating less than usual, less than  desired, or less of the foods they enjoy, rather than by an actual calorie deficiency. Preoccupation with food is defined as the amount of time spent thinking about food. As food, eating, and weight begin to dominate the dieter’s thoughts, the dieter becomes more likely to consume larger portions of his or her favorite foods. This preoccupation with food often leads to the dichotomous thinking of foods in terms of “good” and “bad.” Dichotomous thinking is frequently seen in anorexic patients. As their disease progresses, more foods are labeled “bad” and are restricted.

Types Of Diets

There  are  currently  many  diverse  types  of  diet plans available. Diets vary extensively in calorie intake, type of food restriction, flexibility, duration, and manageability. The key to diet selection is making an  educated,  well-informed  decision.  Some  diets are simply not physiologically sound and may impose  health  threats  that  supersede  weight  loss. For example, many people either restrict calories or stop eating altogether to lose weight. When the body receives cues that food is scarce (i.e., limited food intake), the body attempts to prepare for periods of limited food. The body’s metabolism slows down to avoid demanding more food when none is available. The effect of this slowed metabolism on the modern dieter is the opposite of the intended purpose. That is, the dieter experiences rapid weight gain once normal eating patterns ensue.

Some diets substitute one or more meals with a meal replacement shake or bar. The aim of meal replacement or formula diets is to provide the dieter with necessary nutrients while minimizing excessive calories. There are two central advantages to formula diets: they are easy to follow and they reduce the decision-making process. There are also several disadvantages to formula diets: they are monotonous and the dieter does not learn to make healthy food choices. Furthermore, formula diets that are extremely restrictive (e.g., 300 calories per day) can be detrimental to health.

Different diets emphasize varying aspects of nutrition. For example, high-protein diets stress the importance of the amino acids contained in protein and avoid carbohydrates. High-protein diets usually cause rapid initial weight loss because of the reduction in carbohydrates, which causes water loss. High-protein diets generally do not count calories and are often high  in  saturated  fat.  These  diets  may  produce dangerous effects on the body because of the fat content and the excessive amounts of uric acid released.

On the other end of the dieting spectrum are high-carbohydrate, high-fiber diets. High-carbohydrate diets stress the importance of nutrients contained in vegetables, fruits, nuts, and whole grains. High-carbohydrate diets may assist the dieter’s feeling of satiation due to the high-fiber content. High-carbohydrate diets exhibit slower weight loss over an extended period of time. These diets can be dangerous if the calories are too low or if the protein or fat intake is insufficient to fulfill nutritional needs.

Yet other diets advocate food combinations to promote weight loss. These diets generally do not count calories and are structured around combining different food sources. Food combination diets vary in terms of the nutrients obtained and the well-roundedness of the food selections. Some of these diets (e.g., the Beverly Hills Diet, Jane Fonda, Bloomingdale’s Eat to Succeed) can cause vitamin and mineral deficiencies. Dieters should search for well-balanced diets containing adequate protein, vitamin, and mineral sources.

In opposition to the food combination diets are the food segregation diets that separate different types of food sources. For example, Suzanne Somer’s Get Skinnier on Fabulous Food advocates separating protein and carbohydrate sources. This diet is based on the assumption that when protein and carbohydrates are consumed at the same time, their enzymes cancel each other out, creating a halt in digestion and causing weight gain. However, there is no scientific research to support this claim. Furthermore, the high-fat content may put dieters at risk for heart disease or high cholesterol.

The most successful diets promote lifestyle changes involving both eating and exercise behaviors. A healthy diet should consist of moderate-sized portions of a wide variety of foods to ensure that proper nutrients are obtained. Dieters should avoid diets promising a “quick fix” to weight problems or other solutions that seem too good to be true. Dieters should instead seek out  well-rounded  diet  plans  that  promote  gradual, long-term weight loss and advocate lifestyle changes.

References:

1. Bartlett, J., Wadden, T. A., & Vogt, R. A. (1996). Psychosocial consequences of weight cycling. Journal of Consulting and Clinical Psychology, 64, 587–592.

2. Encyclopedia Britannica Online. (n.d.). Dieting. Retrieved from http://www.britannica.com/ebc/article-9030400
3. Friedman, A., Schwartz, M. B., & Brownell. K. D. (1998). Differential relation of psychological functioning with history and experience of weight cycling. Journal of Consulting and Clinical Psychology, 66, 646–650.
4. Heatherton, T. F., Herman, P., Polivy, J., King, G. A., & McGree, S. T. (1988). The (mis)measurement of restraint: An analysis of conceptual and psychometric issues. Journal of Abnormal Psychology, 97, 19–28.
5. Lattimore, P. , & Halford, J. C. (2003). Adolescence and the diet-dieting disparity: Healthy food choice or risky health behavior? British  Journal  of  Health  Psychology,  8,451–464.
6. Lowe, R. (1993). The effects of dieting on eating behavior.Psychological Bulletin, 114, 100–121.
7. Mayo (n.d.). Popular diets: The good, the fad and the iffy. Retrieved from http://mayoclinic.com/invoke.cfm? id=HQ00654
8. Polivy, , & Herman, C. (1985). Dieting and binging: A causal analysis. American Psychologist, 40, 193–201.
9. Timmerman, M., & Gregg, E. K. (2003). Dieting, perceived deprivation, and preoccupation with food. Western Journal of Nursing Research, 25, 405–418.
10. University of Michigan Health System. (n.d.). Weight-loss diets. Retrieved from http://med.umich.edu/1libr/aha/aha_ odiet_crs.htm
11. Wadden, T. , Brownell,  K.  D.,  &  Foster,  G.  D.  (2002).Obesity: Responding to the global epidemic. Journal of Consulting and Clinical Psychology, 70, 510–525.
12. Worthington-Roberts, (2004). Human nutrition. Retrieved from http://encarta.msn.com/text