A healthy diet will give you about 2500 calories per day for men or 2000 calories for women. Within this, there are certain simple ways to check that your intake is healthy:

Aim to eat 5 portions of fruit and vegetables a day. Potatoes don't count for this although they are good in other ways. A portion is generally about a handful, and to ensure a good mix you should aim to have 2 or 3 different colours of fruit and veg each day too.

Generally, get a little protein with each meal, whether from meat or fish, eggs, nuts, soya or other sources.

Have some starch - rice, bread, potatoes - though try not to have it too fatty, eg steamed rice is healthier than fried (it won't hurt you to have a few things cooked in fat or oil - just not all the time.)

Drink at least a litre of water every day - we often feel hungry when we are really thirsty.

You can find more tips here.