What is a diet?

According to Merriam-Webster, a diet is:

1. food or drink regularly consumed (noun)
2. habitual nourishment (noun)
3. the kind and amount of food prescribed for a person for a special reason (noun)

As a surgeon, this is how I used to define “diet.” When I’m caring for my patients in the hospital, I select their diet. And I make my selections according to their needs:

• High blood pressure? Low sodium diet.
• Weak kidneys? Low potassium diet.
• Diabetes? Low sugar diet.

Made sense to me! A diet is simply what someone eats. And you pick what you eat based on what your body needs, right? It turns out a diet is not that simple. It doesn’t just address a physical need. It incorporates mental and emotional needs too. And that’s how it gets complicated.

What is a diet … really?

Merriam-Webster also offers these definitions of diet:

1. A regimen of eating and drinking sparingly so as to reduce one’s weight (noun)
2. To eat sparingly or according to prescribed rules (verb)
3. Re...