Diet questions
What makes a diet sustainable?
A sustainable diet is one you can keep eating in a normal week, with work, family meals, a birthday and a tight budget, without feeling hungry or deprived. It covers your nutrition needs, uses food you like and can afford, and bends when life gets messy. If you can picture eating this way a year from now, it is probably sustainable.
7 signs a diet will last
Willpower gets you through week one. These are what get you through month six.
- You are not hungry most of the day. Meals with protein, fibre and some fat, like eggs with wholegrain toast or lentil soup with bread, keep you full for hours.
- It covers the basics. Plenty of vegetables, fruit, whole grains or other fibre, and enough protein. A plan that leaves out whole food groups needs a clear reason and a way to replace what is missing.
- You like the food. If you are forcing down meals you dislike, the plan has an end date whether you choose it or not.
- It fits your budget. Beans, oats, frozen vegetables, eggs and tinned fish are cheap. A plan built on specialty bars and shakes gets expensive fast.
- It works at the table with other people. You can eat a family dinner, a work lunch or a meal out without a special order every time.
- It has room for slips. One slice of cake at a party is just one slice of cake, not a reason to start again on Monday.
- It fits your culture and routine. Your usual foods, your cooking time and your work hours are built in, not fought against.
A quick test for any plan
Before you start, or a few weeks in, ask yourself:
- Could I eat this way on a busy Tuesday with 20 minutes to cook?
- Could I eat this way on holiday or at a friend's house?
- Does my weekly shop cost about the same as before, or less?
- Am I thinking about food all day?
- Would I be happy if my kids or partner ate like this too?
Two or more worrying answers usually mean the plan needs changing, not that you need more discipline.
Signs a plan won't last
| Sustainable | Hard to sustain |
|---|---|
| Modest calorie deficit you barely notice | Very low calorie targets that leave you shaky and tired |
| Swaps within foods you already eat | A whole new shopping list of unfamiliar foods |
| Flexible guidelines | Strict rules with "cheat days" |
| Normal groceries | Branded products you must keep buying |
The other meaning of "sustainable diet"
You may also see the phrase used about the planet. Groups such as the WHO and the UN's food agency use "sustainable diet" for eating patterns that are healthy and also easier on land, water and climate. In practice that usually means more plants, beans and whole grains, and less red and processed meat. The good news is that the two meanings overlap a lot: a Mediterranean-style or plant-forward way of eating scores well on both.
Related questions
Is a sustainable diet the same as a healthy diet?
Not quite. A healthy diet is about what the food does for your body. A sustainable diet is one you can actually keep eating. The goal is a pattern that is both, and a healthy plan you quit after three weeks helps less than a decent plan you keep for years.
Can a low-carb or keto diet be sustainable?
For some people, yes. If you enjoy the food, your blood tests stay in a good range and you are not missing fibre, it can last. Many people find strict keto hard to keep up at social meals, so a looser low-carb pattern often works better long term.
How do I make my current diet more sustainable?
Keep the parts that are working and loosen the rules that make you miserable. Add back a food you miss in a planned portion, cook a few reliable meals in bulk, and check that you are eating enough protein and fibre to stay full.
Keep reading
See the difference between a diet and a lifestyle change and how long to give a diet. For a pattern with a long track record, read the Mediterranean diet guide or healthy eating basics. The glossary explains diet quality and a calorie deficit, and how to choose a diet walks you through picking one that fits.