Is it necessary to eat all food groups at every meal?

Eating a varied and well-balanced diet means eating a variety of foods from each of the 5 food groups on a daily basis, in the recommended amounts. Because different foods provide different types and amounts of key nutrients, it's important to choose a variety of foods from each food group. It also means that individual foods and dishes with mixed ingredients (such as pizzas or sandwiches) can have variety. In the United Kingdom, for example, the NHS Eatwell Guide divides foods into food groups (starchy carbohydrates, fruits and vegetables, dairy products or dairy alternatives, proteins and fats).

One of the reasons the variety of foods is included in the recommendations is because different foods have different nutrients. According to this definition, eating a chocolate cake and a strawberry cake would be a form of variety, since they differ in flavor, despite having a very similar nutritional profile and belonging to the same food group. It's important to think about the variety of foods, because research shows that people eat more when foods and foods differ in appearance, flavor, and texture within the same plate. For this reason, eating a variety of foods that belong to a food group (with the exception of fruits and vegetables) has been linked to having a higher body weight.

To achieve the right balance, variety should be encouraged in some food groups, such as fruits and vegetables, but not in others.

Although participants often identified and analyzed different types of variety, they tended to define variety only as the consumption of foods from different food groups as part of a whole diet, a definition consistent with the use of variety in dietary guidelines.

For example, they were shown supermarket aisles with different food brands, meals that consisted of several foods from different food groups and combined dishes, and foods that contained different flavors, colors, and textures, such as salads with a mix of vegetables or pizzas with different ingredients. Importantly, research has also found that variety can refer to foods that differ in their characteristics (such as their appearance, taste, texture, or smell), as well as in the nutrients they contain. To eat a “balanced” diet, the guide recommends that people try to eat a certain amount of foods from each food group.