Yo-yo dieting
Encyclopedia
Yo-yo dieting or Yo-yo effect, also known as weight cycling The term "yo-yo dieting" was coined by Kelly D. Brownell
Kelly D. Brownell
Kelly D. Brownell is an American scientist, professor, and internationally renowned expert on obesity. Brownell is Director of the Rudd Center for Food Policy and Obesity at Yale, where he is also Professor of Psychology and Professor of Epidemiology and Public Health...

, Ph.D., at Yale University
Yale University
Yale University is a private, Ivy League university located in New Haven, Connecticut, United States. Founded in 1701 in the Colony of Connecticut, the university is the third-oldest institution of higher education in the United States...

, in reference to the cyclical up-down motion of a yo-yo
Yo-yo
The yo-yo in its simplest form is an object consisting of an axle connected to two disks, and a length of twine looped around the axle, similar to a slender spool...

. In this process, the dieter is initially successful in the pursuit of weight loss
Weight loss
Weight loss, in the context of medicine, health or physical fitness, is a reduction of the total body mass, due to a mean loss of fluid, body fat or adipose tissue and/or lean mass, namely bone mineral deposits, muscle, tendon and other connective tissue...

 but is unsuccessful in maintaining the loss long-term and begins to gain the weight back. The dieter then seeks to lose the regained weight, and the cycle begins again.

Causes

The reasons for yo-yo dieting are varied but often include embarking upon a hypocaloric diet that was initially too extreme. At first the dieter may experience elation at the thought of loss and pride of their rejection of food
Food
Food is any substance consumed to provide nutritional support for the body. It is usually of plant or animal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals...

. Over time, however, the limits imposed by such extreme diets cause effects such as depression
Depression (mood)
Depression is a state of low mood and aversion to activity that can affect a person's thoughts, behaviour, feelings and physical well-being. Depressed people may feel sad, anxious, empty, hopeless, helpless, worthless, guilty, irritable, or restless...

 or fatigue
Fatigue (physical)
Fatigue is a state of awareness describing a range of afflictions, usually associated with physical and/or mental weakness, though varying from a general state of lethargy to a specific work-induced burning sensation within one's muscles...

 that make the diet impossible to sustain. Ultimately, the dieter reverts to their old eating habit
Habituation
Habituation can be defined as a process or as a procedure. As a process it is defined as a decrease in an elicited behavior resulting from the repeated presentation of an eliciting stimulus...

s, now with the added emotional effects of failing to lose weight by restrictive diet. Such an emotional state leads many people to eating more than they would have before dieting, causing them to rapidly regain weight.

Effects on health

This kind of diet is associated with extreme food deprivation as a substitute for good diet and exercise techniques. As a result, the dieter may experience loss of both muscle
Muscle
Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...

 and body fat during the initial weight-loss phase (weight-bearing
Weight training
Weight training is a common type of strength training for developing the strength and size of skeletal muscles. It uses the weight force of gravity to oppose the force generated by muscle through concentric or eccentric contraction...

 exercise is required to maintain muscle). After completing the diet, the dieter is likely to experience the body's starvation response
Starvation response
Starvation response in animals is a set of adaptive biochemical and physiological changes that reduce metabolism in response to a lack of food....

, leading to rapid weight gain of only fat. This is a cycle that changes the body's fat-to-muscle ratio, one of the more important factors in health. One study in rats showed those made to yo-yo diet were more efficient at gaining weight.
However, as of 1994, the research compiled by Atkinson et al. (1994) showed that there are “no adverse effects of weight cycling on body composition, resting metabolic rate, body fat distribution, or future successful weight loss”, and that there is not enough evidence to show risk factors for cardiovascular disease being directly dependent on cyclical dieting patterns. Yo-yo dieting can have extreme emotional and physical ramifications due to the stress that someone puts on themselves to lose weight quickly. The instant gratification of losing the weight eventually gives way to old eating habits that cause weight gain and emotional distress.

Since there is “no single definition of weight cycling [that] can be endorsed”, it is almost impossible for research to draw specific conclusions about the actual affects of cyclical dieting, until it becomes more definitely defined.

See also

  • Healthy diet
    Healthy diet
    A healthy diet is one that helps maintain or improve general health. It is important for lowering many chronic health risks, such as obesity, heart disease, diabetes, hypertension and cancer. A healthy diet involves consuming appropriate amounts of all essential nutrients and an adequate amount of...

  • Food faddism
    Food faddism
    The phrases food faddism and fad diet originally referred to idiosyncratic diets and eating patterns that promote short-term weight loss, usually with no concern for long-term weight maintenance, and enjoy temporary popularity...

  • Food Balance Wheel
    Food Balance Wheel
    The Food Balance Wheel suggests an alternate interpretation of the USDA Food Guide Pyramid recommendations for balanced eating. Created by author Art Dragon, it converts the principles of the food pyramid from a number-based format to a visual presentation that may be more accessible to users...

  • Excess post-exercise oxygen consumption
    Excess post-exercise oxygen consumption
    Excess post-exercise oxygen consumption is a measurably increased rate of oxygen intake following strenuous activity intended to erase the body's "oxygen debt." In historical context the term "oxygen debt" was popularized to explain or perhaps attempt to quantify anaerobic energy expenditure,...

    (EPOC)

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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