What does diet mean?
Diet refers to the range of foods that a person, animal, or population regularly consumes, as in 'the typical American diet' or 'the panda's diet consists almost entirely of bamboo.' In its second common sense, a diet is a deliberately restricted or modified pattern of eating adopted for health, medical, or weight-loss purposes, as in 'she started a new diet in January.' The word carries both neutral and loaded connotations: scientists may discuss diets purely descriptively, while in popular culture 'going on a diet' implies restraint and self-discipline, sometimes with undertones of deprivation. Derived forms include 'dietary,' 'dieter,' and 'dieting.' The verb form means to eat according to such a restricted plan. Because eating habits are central to culture and health, diet appears frequently in medicine, nutrition science, journalism, and everyday conversation alike.
The kinds of food that a person, animal, or community habitually eats.
"Koalas survive on a diet consisting almost entirely of eucalyptus leaves."
Neutral, descriptive sense used widely in nutrition and science.
A restricted or regulated selection of food followed to lose weight or improve health.
"He abandoned his strict diet after just two weeks."
Often appears in the fixed phrase 'go on a diet.'
To eat according to a restricted regimen, typically in order to lose weight.
"She has been dieting steadily since the new year."
The plural typically refers to the eating patterns of different people, groups, or species, rather than multiple regimens of one person.
"Diets high in processed meat are associated with increased health risks."
The word 'diet' originally meant 'a way of living' — so technically, everyone has always been on a diet.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of diet
The word 'diet' comes from Middle English 'diete', borrowed from Old French, ultimately from Latin 'dieta', meaning 'a day's allowance of food' or more broadly 'way of living.' The Latin term itself derived from Greek 'diaita', signifying 'manner of living.' Over time the sense narrowed from one's overall way of life to the specific matter of food consumed. A related but distinct sense of 'diet' meaning a formal legislative assembly (as in the Diet of Worms) arose separately through Germanic usage of the same Latin root.
Related word forms
How diet is actually used
In everyday use, 'diet' often carries connotations of weight loss and restriction, even though its neutral sense simply means what one eats. The phrase 'on a diet' almost always implies deliberate restriction. As a verb ('to diet'), it means specifically to restrict food intake to lose weight.
Easily confused with diet
This is not an English word — the correct spelling is 'diet', which refers to habitual food intake or a food regimen.