This is a surprisingly common question that is asked and one where the answer can be found fairly quickly by doing some research. It is common sense that you should aim to consume less calories then you burn off through exercise and everyday movement. Not doing so will cause you to have a calorie surplus and in turn will mean that you may put on weight. Obviously there are lots of other factors involved that will dictate how much weight a person puts on, some people appear not to put on weight at all.
Government information suggests that the ideal daily intake for males is 2500Kcal and for women it's 2000Kcal. These figures act as a guide to ensure that you stay at a healthy weight. Unfortunately in this day and age, and with the amount of cheap and easy to obtain processed food, a lot of people tend to consume over their recommended calorie intake. This in conjunction with not doing enough physical exercise leads to obesity. A very good guide to healthy eating is the Governments Eatwell Guide - The Eatwell Guide is a policy tool used to define government recommendations on eating healthily and achieving a balanced diet.
The main thing is to know what you are eating, make sure you are eating enough healthy nutrient enriched food and not to miss meals out, especially a good breakfast. I am a firm believer that a good breakfast sets you up for the day, and can stop you consuming foods that are full of calories later on, when your energy levels drop. Try tracking your calories for a week using one of the many free calorie counter apps available. It will surprise you how many calories are in supposedly healthy foods.
Things to avoid
Firstly trans fats. They can raise bad cholesterol and reduce good cholesterol, increasing the risk of heart disease. Replace foods high in saturated and trans fat such as butter, whole milk, and baked goods with foods higher in unsaturated fat found in plants and fish, such as vegetable oils, avocado, and tuna fish.
Cut down on your sugar intake, such as fizzy drinks and snacks like cakes & sweets biscuits – they should be a treat and not an everyday occurrence. Start by cutting sugar from your hot drinks and cereals, its about making small steps.
Watch your portion size. It is very common for people to load up their plate and eat far more food than is required.
Limit the amounts of alcohol you drink. Try and leave a day between drinking and drink water in between alcoholic drinks.
Beware of liquid calories – such as soft drinks, juices and alcoholic drinks.
The good things
Consume a variety of foods. Try and balance your meals with protein, complex carbs, lots of vegetables, fruit and wholegrains.
Consume a variety of foods and balance your meals with protein, complex carbs, wholegrain, and lots of fruit and veg. Try lower fat dairy or dairy alternatives, i.e. almond or soya milk.
Eat nuts, beans, pulses, lentils and eggs (boiled or poached).
Try to eat oily fish twice and week, and consume more white meat like chicken and turkey, and consume food over supplements.
Try to drink two litres of water a day. Put a timer on your phone so you are reminded when to go and get a drink.
Consume more potassium (bananas, potatoes, beans and yogurts). Studies have shown that potassium has a positive effect on blood pressure. It may curb elevated blood pressure by contributing to more flexible arteries, and by helping the body get rid of excess sodium. Sodium promotes fluid retention, which may result in higher blood pressure.
Increase your vitamin D and calcium intake. We need vitamin D to help the body absorb calcium and phosphate from our diet. These minerals are important for healthy bones, teeth and muscles. We get vitamin D direct from the sun, but it can also be obtained from some foods, such as oily fish and eggs and from supplements.