Many authorities recommend dietary guideline to address this issue, and developed educational tools to guide population; for example the MyPlate of USA and Eat Well Plate of UK are pictorial tools to guide proper intake (not over/under consumption). The concept is customized for may population groups in many countries. For example we developed the concept for pregnant women of Bangladesh (Shamim, Abu Ahmed, et al. "Designing a food plate for dietary counselling of pregnant women in Bangladesh." Field Exchange 52 (2016): 116.)

It is really hard to find out what comprises a good balanced diet, given the variations in individual needs based on the types of occupation, activity, health and physiological status. Nutritional quality varies also with the types of available crops and the preparation techniques used to make diets.

But countries have a general guidelines based on the population practices and status. It is therefore, dependent on the country or the population you have in mind.

Generally, the recommendations for adult consumers are higher frequencies of less refined whole grain based foods with rich micro-nutrients, fiber and bioactive (antioxidant) compounds. The general recommendation is less fat and added sugar as well as less than moderate alcohol consumption.

Physical activities and the habit of sporting is also highly recommended for a better healthy life. I hope this helps.