Eat as many coloured vegetables as you can . Buy vegetables and fruits like capsicums ( red, green and yellow ), carrots, cabbages white and red, different coloured Apples etc mix them up in salads, side dishes and so on.
They give you as many different phytochemicals as possible if you can add all of them and mix them up.
Variety is the sppice of life and we all agree to that isn't it?
Do that for eating also. Mix up vegetables and fruits with your fast foods , non vegetarian items etc. You will get enough vitamins and minerals through that.
Try out new recipes from different cuisines, not only that they taste different, their mix will be different and their values will be different.
While eating always have one from each group, carbohydrates, Proteins, Vitamins & Minerals.
Use herbs and spices for flavouring instead of salt, pepper, chilli powder and sugar.
Avoid buying and eating anything which is man made and prepacked, with this rule you can avoid most of the processed goods which are really bad for health. Think of what your great grandmother and grandmother would have given you if they were alive.
Those are the good and healthy foods which is very close to nature.
The main thing is to teach children to stay away from the endorsements which the celebrities make. Will your advertisers really eat them ? Have you ever really thought about it? No they will not. For example they advertise for aerated drinks, but will they ever drink them? I don't think so.
Children are the ones who fall for the advertisements and ask for those products. Teach children, tell them about the products or just give them once or twice in a month to satisfy them.