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diet

1 American  
[dahy-it] / ˈdaɪ ɪt /

noun

  1. food and drink considered in terms of its qualities, composition, and its effects on health.

    The ad shows milk and dairy as a wholesome part of our daily diet.

  2. a particular selection of food, especially as designed or prescribed to improve a person's physical condition or to prevent or treat a disease.

    A diet low in sugar is often recommended for diabetes prevention.

  3. a selection of food that emphasizes caloric restriction or otherwise limits the amount a person eats, usually intended to induce weight loss.

    No pie for me, I'm on a diet.

  4. the foods eaten, as by a particular person or group.

    The Mediterranean diet consists historically of fish, fruit, vegetables, whole grains, and nuts.

  5. food or feed habitually eaten or provided.

    The rabbits were fed a diet of carrots and lettuce.

  6. anything that is habitually provided or partaken of.

    Television has given us a steady diet of reality shows and police procedurals.


adjective

  1. suitable for consumption as part of a selection of food intended to induce weight loss.

    I usually drink diet soft drinks.

  2. formulated to be lower in calories, fat, sugar, etc. than a similar food.

    The diet version of the cookie does taste different.

verb (used without object)

  • diets,
    present (3rd person singular)
  • dieted,
    past participle,  past
  • dieting
    present participle
  1. to select or limit the food one eats to improve one's physical condition or to lose weight.

    I've dieted all month and lost only one pound.

  2. to eat or feed according to the requirements of a particular or prescribed selection of food.

verb (used with object)

  • diets,
    present (3rd person singular)
  • dieted,
    past participle,  past
  • dieting
    present participle
  1. to regulate the food of, especially in order to improve the physical condition.

    They dieted the dog to a healthy weight of 20 pounds.

  2. to feed.

diet 2 American  
[dahy-it] / ˈdaɪ ɪt /

noun

  1. the legislative body of certain countries, as Japan.

  2. the general assembly of the estates of the former Holy Roman Empire.


diet 1 British  
/ ˈdaɪət /

noun

    1. a specific allowance or selection of food, esp prescribed to control weight or in disorders in which certain foods are contraindicated

      a salt-free diet

      a 900-calorie diet

    2. ( as modifier )

      a diet bread

  1. the food and drink that a person or animal regularly consumes

    a diet of nuts and water

  2. regular activities or occupations

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

verb

  1. (usually intr) to follow or cause to follow a dietary regimen

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
diet 2 British  
/ ˈdaɪət /

noun

  1. (sometimes capital) a legislative assembly in various countries, such as Japan

  2. Also called: Reichstag. (sometimes capital) the assembly of the estates of the Holy Roman Empire

  3. Scots law

    1. the date fixed by a court for hearing a case

    2. a single session of a court

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

Derived Forms

Inflected Forms

Participles

Conjugated Forms

Present

Past

Future


Etymology

Origin of diet1

First recorded in 1175–1225; Middle English noun diete “day’s journey, appointed day, way of living,” from Anglo-French, Old French diete, from Latin diaeta, from Greek díaita “way of living, diet,” equivalent to dia- dia- + -aita (akin to aîsa “share, lot”; the verb is derivative of the noun

Origin of diet2

First recorded in 1400–50; late Middle English, from Medieval Latin diēta “public assembly,” the same word as Latin diaeta with sense affected by Latin diēs “day”; see diet 1


Explanation

Diet means the usual food and drink consumed by a person or animal. A healthy diet for your pet is not the same as your diet, so you shouldn't feed your dog all your table scraps. If you limit the number of calories you eat in order to lose weight, or restrict certain foods for your health, you can also call this a diet. If you want to lose 10 pounds by summer, you might have to go on a diet. In certain countries, the word diet, though pronounced the same, has a non-food related meaning: the diet is the legislative branch of the government in countries like Japan.

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Vocabulary lists containing diet

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

Boucher said that Luna likely survived on an abundance of water and wild animal scat, though it’s not quite exactly known what her diet or shelter situation was.

From Los Angeles Times ● Oct. 17, 2026

"So I think the costs of a healthy diet, which means an increased cost on legumes, on vegetables, on meat, is just having a big impact on what people can afford to consume."

From Barron's ● Oct. 16, 2026

There’s also the 5:2 diet, which involves eating normally five days out of the week, and consuming just 25% of your normal caloric intake the other two days.

From MarketWatch ● Oct. 16, 2026

My sport-obsessed son, who already eats a healthy balanced diet, asks me about protein powder on a regular basis.

From BBC ● Oct. 15, 2026

“I’ve had those diet frozen pizzas, but they taste like card board, and they don’t look anything like the ones they sell in pizza places. The melting cheese, the pepperoni.”

From "Sparrow" by Sarah Moon

Among American consumers, it was more popular than eating low-carb or Mediterranean diets, according to a recent survey.

From MarketWatch ● Oct. 16, 2026

They’re coming up with diets for people to follow and ordering the groceries.

From The Wall Street Journal ● Oct. 16, 2026

The researchers collected anonymous survey responses from approximately 400 college students, gathering information about their diets, sleep patterns, exercise habits, and other lifestyle factors.

From Science Daily ● Oct. 13, 2026

The findings, published online Sept. 30 in the journal Nature, also showed that sugary diets combined with antibiotic treatment were associated with increases in Enterococcus faecium among patients.

From Science Daily ● Oct. 7, 2026

The Mexican songs were constantly punctuated by irrelevant spotshots nobody listened to, such as the “German Press Review” and a show featuring a well-known beauty queen talking to teen-agers about their diets and their pimples.

From "The Milagro Beanfield War" by John Nichols

“I just couldn’t look like that no matter how much I dieted or went to the gym.”

From The Wall Street Journal ● May 4, 2026

“Apartments without dining rooms, as if anticipating a future where families disintegrated, compulsively dieted, or ate alone, in front of televisions.”

From Los Angeles Times ● May 15, 2024

For example, one study revealed that compared with daughters of nondieting women, 5-year-old girls whose mothers dieted were aware of the connection between dieting and thinness.

From Salon ● Feb. 22, 2024

The sales rep said: "I yo-yo dieted my whole life, for 30 years, and I got my sleeve two years ago."

From BBC ● Jan. 15, 2024

She binged and dieted and then cycled through it all again.

From "Zeitoun" by Dave Eggers

Both were usually euphemisms for the same thing: I was dieting, and I had already begun the day’s arithmetic.

From Salon ● Aug. 31, 2026

“Lisa” represents a woman in her late 30s or 40s with a long history of dieting.

From The Wall Street Journal ● Aug. 19, 2026

They viewed 10 potentially harmful videos focused on dieting and body image, mimicking the behaviour of a new user showing interest in that kind of content.

From BBC ● Jul. 13, 2026

These concerns have influenced public opinion and even medical advice, leading some people to believe repeated dieting attempts may ultimately cause more harm than benefit.

From Science Daily ● May 17, 2026

The dieting eventually stopped when I hit middle school.

From "Dumplin'" by Julie Murphy

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