Weight cycling, also known as yo-yo dieting, is the repeated loss and gain of weight, resembling the up-down motion of a

yo-yo A yo-yo (also spelled yoyo) is a toy consisting of an axle connected to two disks, and a string looped around the axle, similar to a spool. It is an ancient toy with proof of existence since 440 BC. The yo-yo was also called a bandalore in th ...

. The temporary weight loss of yo-yo dieting is often caused by quick yet unsustainable success of strict diets. The dieter often gives up due to hunger or discomfort, and gains the weight back. The dieter then seeks to lose the regained weight, and the cycle begins again. Other individuals cycle weight deliberately in service of

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or athletic goals. Weight cycling contributes to increased risk of later obesity, due to repeated signals being sent to the body signalling that it's in starvation mode; therefore it learns to be better and better at storing fat, and increases the strain on vital organs, likely promoting cardiometabolic disease.

Causes

Dieting

The reasons for yo-yo dieting are varied but often include embarking upon a hypocaloric diet too extreme to maintain. At first the dieter may experience elation at the thought of

weight loss Weight loss, in the context of medicine, health, or physical fitness, refers to a reduction of the total body mass, by a mean loss of fluid, body fat (adipose tissue), or lean mass (namely bone mineral deposits, muscle, tendon, and other conn ...

and pride in their self-control for resisting certain foods, e.g. junk food, desserts, and sweets. Over time, however, the limits imposed by such extreme diets cause effects such as depression or

fatigue Fatigue is a state of tiredness (which is not sleepiness), exhaustion or loss of energy. It is a signs and symptoms, symptom of any of various diseases; it is not a disease in itself. Fatigue (in the medical sense) is sometimes associated wit ...

that make the diet impossible to sustain. Ultimately, the dieter reverts to their old eating

habit A habit (or wont, as a humorous and formal term) is a routine of behavior that is repeated regularly and tends to occur subconsciously. A 1903 paper in the '' American Journal of Psychology'' defined a "habit, from the standpoint of psychology, ...

s, now with the added emotional effects of failing to lose weight by the restrictive diet. Such an emotional state leads many people to eating more than they would have before dieting, especially the 'forbidden' foods e.g. junk food, desserts, and sweets, causing them to rapidly regain weight.

Sports

In some sports where an athlete's weight is important, such as those that use

weight class Weight classes are divisions of competition used to match competitors against others of their own size. Weight classes are used in a variety of sports including Rowing (sport), rowing, Weightlifting#Weightlifting sports, weight lifting, and especi ...

es or aesthetics, it is common for athletes to engage in weight cycling. Weight cycling is common among competitive

combat sports A combat sport, or fighting sport, is a contact sport that usually involves one-on-one combat. In many combat sports, a contestant wins by scoring more points than the opponent, submitting the opponent with a hold, disabling the opponent (''knocko ...

athletes, including minors. In

and strength sports, weight cycling is often used as a way to take advantage of the increased ability to gain muscle while in a caloric surplus by cyclically going through periods of intentional weight gain, followed by a period of weight loss to prevent excessive body fat accumulation.

Mechanism

The process of regaining weight and especially body fat is further promoted by the high metabolic plasticity of skeletal muscle. The Summermatter cycle explains how skeletal muscle persistently reduces energy expenditure during dieting. In addition, food restriction increases physical activity which further supports body weight loss initially. Such weight regain in the form of preferential catch-up-fat is well documented after weight loss due to malnutrition, cancer, septic shock or AIDS and thus constitutes a general phenomenon related to weight loss.

Health effects

Weight cycling might have negative health effects from repeated strain on the body. A 2019 systematic review and meta-analysis found that "Body-weight fluctuation was associated with higher mortality due to all causes and CVD and a higher morbidity of CVD and

hypertension Hypertension, also known as high blood pressure, is a Chronic condition, long-term Disease, medical condition in which the blood pressure in the artery, arteries is persistently elevated. High blood pressure usually does not cause symptoms i ...

." A 2019 review found that self-reported weight cycling was correlated with an increased risk of endometrial cancer. Weight cycling is also correlated with

kidney cancer Kidney cancer, also known as renal cancer, is a group of cancers that starts in the kidney. Symptoms may include blood in the urine, a lump in the abdomen, or back pain. Fever, weight loss, and tiredness may also occur. Complications can include ...

, independently of whether the person is overweight. A 2021 systematic review and meta-analysis found that "weight cycling was a strong independent predictor of new-onset

diabetes Diabetes mellitus, commonly known as diabetes, is a group of common endocrine diseases characterized by sustained high blood sugar levels. Diabetes is due to either the pancreas not producing enough of the hormone insulin, or the cells of th ...

". Weight cycling is also associated with poorer mental health.

References