What affect will the consumption of food and drink have?
Your character can get fat by eating and drinking too much, but will get thinner due to exercise and energy expenditure. Every type of food and drink has an associated calorific value each gives a set amount of energy (health) and fat. The general purpose of food is to increase your health. But any fat will be added to your characters overall fat value, as will any excess energy (e.g. if you already have full health).