Definition of Diet

Elise Deming, RDN
Woman in kitchen with fresh produce

The world "diet" can elicit a wide variety of possible meanings and connotations, depending on the context. Diets are also oftentimes recommended for a myriad of reasons.

What Is a Diet?

The Merriam-Webster dictionary provides multiple definitions of a diet including:

  • Food and drink regularly consumed
  • Habitual nourishment
  • The kind and amount of food prescribed for a person or animal for a special reason

These differing definitions are all correct as a diet can be a very abstract concept and there are three common ways to think about a diet. Depending on the health perspective, a diet can be a simple pattern of eating, a set of prescribed nutritional guidelines for someone with a health condition, or a part of a weight loss program.

A Pattern of Eating

"Diet" doesn't necessarily refer to a health promoting eating pattern. It just refers to foods and beverages that are commonly consumed and how they are consumed. There are a wide variety of diets that are simply patterns of eating. Two very common examples include:

  • The Western Diet - This is a pattern of eating popular in westernized countries, especially the United States. This pattern of eating consists of refined and processed foods; foods high in sugar, sodium, and saturated fats; large portions; and fast foods as well as minimal fruits, vegetables, and whole grains.
  • The Mediterranean Diet - Another pattern of eating many people adopt is the Mediterranean Diet. This pattern is known to contain many plant-based nutrients from high amounts of fruits and vegetables, healthy fats from olive oil, limited salt and red meat, and a focus on whole grains, nuts, seeds, and healthy proteins such as fish and poultry.

Disease Related Diet

Diets can be prescribed by registered dietitians or physicians to help heal and manage a disease or medical condition. Evidence exists that disease-specific diets can help people recover from a medical condition or improve quality of life. Common conditions that may receive a diet prescription include:

  • Diabetes
  • Heart disease
  • Hypertension
  • Kidney disease
  • Gastrointestinal disorders
    • Inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS)
    • Celiac disease
    • Constipation or diarrhea
  • Allergies
  • Anemia
  • Cancer

The above is only a small list of medical conditions diets can help treat. If you are suffering from a disease or medical problem, speak with your doctor if a specialized diet could help you.

Weight Loss

The last and arguably the most common reason people reference diets is in the context of weight loss. There are many diets available to promote weight loss. However, not all diets are evidence-based or even safe. Some popular diets include:

  • Atkins - The Atkins diet was designed by a cardiologist. It centers around a low carbohydrate eating pattern. Additionally, the Atkins diet relies on "steady fueling" throughout the day to keep dieters full. Products are available for participants to purchase and recipes for them to cook.
  • South Beach - This diet is low in carbohydrates, but also focuses on changing participants to a more healthful overall diet. The South Beach Diet helps shift individuals to a diet high in lean proteins, better carbohydrates, fruits, vegetables, and healthy fats. This diet also features frequent, small meals throughout the day.
  • Weight Watchers - Weight Watchers encourages participants to "eat more fruits, veggies, lean protein, and less sugar and unhealthy fats." They do this through a points system that gives nutrient dense foods fewer points than foods that aren't as good for you. Additionally, Weight Watchers provides its participants with a support system of meetings, health coaches, and virtual resources.

People see success with different diets for weight loss, making it important to remember that nutrition and dieting is an individualized science. What works for one person may not work for you. Consulting with a registered dietitian can greatly aid and fast track weight loss as well as ensure you are doing it safely.

A Broad Term

A diet is a broad term and can be applied to many situations. A diet can consist of the foods you typically eat, it could refer to the foods recommended to you for a medical condition, or it could something you follow for weight loss. No matter why you follow a diet, always check with a dietitian or healthcare professional before starting.

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Definition of Diet