Dieting is the practice of eating food in a regulated way to decrease, maintain, or increase body weight, or to prevent and treat diseases such as diabetes and obesity. As weight loss depends on calorie intake, different kinds of calorie-reduced diets, such as those emphasising particular macronutrients, have been shown to be no more effective than one another. As weight regain is common, diet success is best predicted by long-term adherence. Regardless, the outcome of a diet can vary widely depending on the individual.
Obesity is a medical condition, sometimes considered a disease, in which excess body fat has accumulated to such an extent that it can potentially have negative effects on health. People are classified as obese when their body mass index (BMI)—a person's weight divided by the square of the person's height—is over 30 kg/m2; the range 25–30 kg/m2 is defined as overweight. Some East Asian countries use lower values to calculate obesity. Obesity is a major cause of disability and is correlated with various diseases and conditions, particularly cardiovascular diseases, type 2 diabetes, obstructive sleep apnea, certain types of cancer, and osteoarthritis.
Binge eating disorder (BED) is an eating disorder characterized by frequent and recurrent binge eating episodes with associated negative psychological and social problems, but without the compensatory behaviors common to bulimia nervosa, OSFED, or the binge-purge subtype of anorexia nervosa.
Binge eating is a pattern of disordered eating which consists of episodes of uncontrollable eating. It is a common symptom of eating disorders such as binge eating disorder and bulimia nervosa. During such binges, a person rapidly consumes an excessive quantity of food. A diagnosis of binge eating is associated with feelings of loss of control. Binge eating disorder is also linked with being overweight and obesity.
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, or lean mass. Weight loss can either occur unintentionally because of malnourishment or an underlying disease, or from a conscious effort to improve an actual or perceived overweight or obese state. "Unexplained" weight loss that is not caused by reduction in calorific intake or increase in exercise is called cachexia and may be a symptom of a serious medical condition.
In nutrition, diet is the sum of food consumed by a person or other organism. The word diet often implies the use of specific intake of nutrition for health or weight-management reasons. Although humans are omnivores, each culture and each person holds some food preferences or some food taboos. This may be due to personal tastes or ethical reasons. Individual dietary choices may be more or less healthy.
Anti-obesity medication or weight loss medications are pharmacological agents that reduce or control excess body fat. These medications alter one of the fundamental processes of the human body, weight regulation, by: reducing appetite and consequently energy intake, increasing energy expenditure, redirecting nutrients from adipose to lean tissue, or interfering with the absorption of calories.
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. The purpose of the temporary weight loss the yo-yo diet delivers is to lure the dieting into the illusion of success, but due to the nature of the diet, they are impossible to sustain, therefore the dieter gives up, often 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 bodybuilding 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.
A healthy diet is a diet that maintains or improves overall health. A healthy diet provides the body with essential nutrition: fluid, macronutrients such as protein, micronutrients such as vitamins, and adequate fibre and food energy.
Childhood obesity is a condition where excess body fat negatively affects a child's health or well-being. As methods to determine body fat directly are difficult, the diagnosis of obesity is often based on BMI. Due to the rising prevalence of obesity in children and its many adverse health effects it is being recognized as a serious public health concern. The term overweight rather than obese is often used when discussing childhood obesity, as it is less stigmatizing, although the term overweight can also refer to a different BMI category. The prevalence of childhood obesity is known to differ by sex and gender.
Health at Every Size (HAES) is a public health framework that emphasizes all bodies have the right to seek out health, regardless of size, without bias, and reduce stigma towards people who are in larger bodies. Proponents argue that traditional interventions focused on weight loss, such as dieting, do not reliably produce positive health outcomes, and that health is a result of lifestyle behaviors that can be performed independently of body weight. However, many criticize the approach and argue that weight loss should sometimes be an explicit goal of healthcare interventions, because of the negative health outcomes associated with obesity.
Bariatric surgery is a medical term for surgical procedures used to manage obesity and obesity-related conditions. Long term weight loss with bariatric surgery may be achieved through alteration of gut hormones, physical reduction of stomach size, reduction of nutrient absorption, or a combination of these. Standard of care procedures include Roux en-Y bypass, sleeve gastrectomy, and biliopancreatic diversion with duodenal switch, from which weight loss is largely achieved by altering gut hormone levels responsible for hunger and satiety, leading to a new hormonal weight set point.
Intermittent fasting is any of various meal timing schedules that cycle between voluntary fasting and non-fasting over a given period. Methods of intermittent fasting include alternate-day fasting, periodic fasting, such as the 5:2 diet, and daily time-restricted eating.
While genetic influences are important to understanding obesity, they cannot explain the current dramatic increase seen within specific countries or globally. It is accepted that calorie consumption in excess of calorie expenditure leads to obesity; however, what has caused shifts in these two factors on a global scale is much debated.
Weight management refers to behaviors, techniques, and physiological processes that contribute to a person's ability to attain and maintain a healthy weight. Most weight management techniques encompass long-term lifestyle strategies that promote healthy eating and daily physical activity. Moreover, weight management involves developing meaningful ways to track weight over time and to identify the ideal body weights for different individuals.
Management of obesity can include lifestyle changes, medications, or surgery. Although many studies have sought effective interventions, there is currently no evidence-based, well-defined, and efficient intervention to prevent obesity.
Coaches are professional tutors who have expertise in their preferred area of study. Weight loss coaches, specifically, have clientele within the health and fitness industry.
Nutrition psychology is the psychological study of the relationship between dietary intake and different aspects of psychological health. It is an applied field that uses an interdisciplinary approach to examine the influence of diet on mental health. Nutrition psychology seeks to understand the relationship between nutritional behavior, mental health and general well-being. It is a sub-field of psychology and more specifically of health psychology, and may be applied to numerous related fields, including psychology, dietetics, nutrition, and marketing.
Jean Harvey, PhD, RDN, is currently the Robert L. Bickford, Jr. Endowed Professor, the Associate Dean for Research, and the Chair of the Department of Nutrition and Food Science in the College of Agriculture and Life Sciences at the University of Vermont. Her specialty is behavioral weight management with a specific focus on technology-based programs.
The Food Cravings Questionnaires (FCQs) are among the most widely used self-report questionnaires for measuring food craving. They were developed by Antonio Cepeda-Benito and colleagues in 2000. For the 39-item trait version (FCQ-T), respondents indicate how frequently each statement is true for them in general on a six-point scale with 1 = never/not applicable, 2 = rarely, 3 = sometimes, 4 = often, 5 = usually, and 6 = always. For the 15-item state version (FCQ-S), respondents indicate the extent to which they agree with each statement right now, at this very moment, on a five-point scale with 1 = strongly disagree, 2 = disagree, 3 = neutral, 4 = agree, 5 = strongly agree.
