Diet types
The main diets, and how they differ
Most diets change just one thing: what you eat, how much, or when. Once you know which rule a diet changes, it gets much easier to tell whether it will suit you.
Mediterranean and DASH change the quality of your food. Low carb and keto cut carbohydrate. Plant-based diets cut animal foods. Intermittent fasting changes when you eat. All of them can work for weight loss if they help you eat a little less without feeling deprived.
The main diets in one line each
| Diet | What it changes | Tends to suit you if |
|---|---|---|
| Mediterranean | More vegetables, beans, fish, olive oil and nuts; less red meat and sweets. | You like cooking, eating out and flexible rules. |
| DASH | Lots of fruit, vegetables and low-fat dairy, with sodium capped at 2,300 mg or 1,500 mg a day. | Your blood pressure is creeping up and you like clear daily targets. |
| Low carb | Less bread, pasta, rice and sugar; more protein, vegetables and fat. | You feel fuller on eggs, meat and cheese than on toast and cereal. |
| Keto | Very low carb, usually under about 20-50 g a day, to push your body into ketosis. | You do well with strict, clear rules and can live without most fruit and grains. |
| Plant-based | Most or all of your food comes from plants, from flexitarian up to fully vegan. | Animal welfare, the planet or eating more fibre matters to you. |
| Intermittent fasting | Limits eating to set hours or days, such as eating between 10am and 6pm. | You would rather skip a meal than count anything. |
Four families of diet
Food-quality patterns
Mediterranean, DASH and plain healthy eating don't ban much. They shift the balance of your plate toward vegetables, beans, whole grains and unsaturated fats. They have strong evidence for heart health and are easy to keep up at family meals and restaurants. Portions still count if you want to lose weight.
Carb-cutting diets
Low carb covers a wide range, from simply dropping sugary drinks and white bread to strict keto. Keto can bring a headache, tiredness and "keto flu" for a few days while your body adjusts. What replaces the carbs matters: salmon and vegetables are not bacon and butter.
Plant-based diets
These range from flexitarian through vegetarian to vegan. Vegan diets need a reliable source of vitamin B12, usually a supplement or fortified foods, and some thought about iron, calcium, iodine and omega-3.
Timing diets
Intermittent fasting and time-restricted eating only change your schedule. They work on top of any diet. In trials, weight loss is usually similar to ordinary calorie cutting.
If you take insulin or other diabetes medicine, are pregnant, have kidney disease or have a history of an eating disorder, talk to your doctor before trying keto, fasting or any strict plan.
How to compare any diet
- Name the main rule: what, how much or when you eat.
- List what gets cut and what replaces it.
- Picture a normal week, with a work lunch and a birthday dinner.
- Ask what happens after three months.
The choose-a-diet guide walks through these steps, and the diet comparison table puts them side by side.
Guides and terms
Mediterranean diet
Olive oil, fish, beans and vegetables, with room for the foods you love.
Read more →DASH diet
Built to lower blood pressure, with daily servings for each food group.
Read more →Keto diet
How very low carb works, the side effects, and who should skip it.
Read more →Low-carb diets
From gentle cutting back to strict limits, and what to eat instead.
Read more →Plant-based diets
Flexitarian, vegetarian or vegan, and the nutrients to plan for.
Read more →Intermittent fasting
16:8, 5:2 and other schedules, plus who shouldn't fast.
Read more →Ketosis
What happens when your body runs mainly on fat and ketones.
Read more →Macronutrients
Carbs, protein and fat, and why diets shuffle them around.
Read more →Elimination diet
Cutting foods out to find a trigger, then adding them back.
Read more →Is there one best diet?
Short answer: no, but some fit you better than others.
Read more →Can I mix diets?
Yes. Mediterranean food in an eating window is a common mix.
Read more →Common questions
What is the healthiest type of diet?
Most health bodies point to Mediterranean and DASH-style eating: plenty of vegetables, fruit, beans, whole grains and fish, with less processed meat, salt and sugar. The healthiest version is one you can keep up for years.
What is the difference between keto and low carb?
Keto is the strictest form of low carb. It usually keeps carbs under about 20-50 g a day so your body makes ketones. Low carb is looser and can mean anything from cutting out sugary drinks to eating around 100 g of carbs a day.
Which diet is easiest to stick to?
Usually the one that asks you to change the least, such as Mediterranean-style eating, where nothing is banned. If you like firm rules, DASH or an eating window may feel easier.