This must be the most complicated subject to write about but also the most important one, especially for beginners. It seems that there are hundreds of diets around for runners all of which contradict each other, but all of which have a little logic. It's hard to know what to believe. The general consensus is that a runner's diet should mainly consist of (60%) carbohydrates. However, a healthy diet should also conist of fats, protein, vitimins, minerals and water. With the rise of the Atkin's diet, many people have come to the conclusion that carbohydrates should be avoided at all costs. The Atkin's diet encourages the consumption of a high-fat-low-carb diet. It is a fact that a gram of fat contains double the amount of calories (kcal) than a gram of carbohydrates, thus, if you want to lose weight, choose carbs over fat.

There are two types of carbohydrates, 'simple' and 'complex'. Runners should be aiming to eat mainly complex carbohydrates, these are found in foods such as rice and pasta, simple carbs are found in foods such as sweet cereals. Simple carbs are sugars and do not provide a steady stream of energy like complex carbs. Carbohydrates are important to distance runners as they provide the main bulk of our muscle glycogen. This is basically energy stored in the muscles. We have around 1, 400 calories stored in this form - you may have heard about hitting 'the wall' during a marathon (26.2 miles), this occurs at any time between mile 15 to mile 20, when our muscles become depleted of glycogen. To help prevent this, distance runners may 'carbo-load'. This involves consuming more carbohydrates than usual over a time period, and should not concern beginners. Generally carboloading bears no benefits on performance for runs under 13 miles. It is important to eat carbohydrates after a run within 30 minutes, to restore energy levels. If you weigh 200 pounds for instance, you should half this figure, and eat the sum you are left with in grams of carbohydrates (this would be 100g of carbs in this instance). This practise becomes more important as your mileage increases and it is also important if you run in the morning, or will be doing physical activity later in the day. The reason food should be consumed within 30 minutes of exercise is because that is when our muscles are the most absorbent.

As for the other 40% of our diet, we should consume around 20% protein and 20% fat. Protein is vital to rebuild our muscles after a run and repairs the damage caused by the trauma of running. Eating extra protein will reap no benefits, you will not build muscle any quicker, and it will not enhance performance, in fact, it is likely to have an opposite effect if you replace carbs with protein. The 20% of fat that we consume should be mainly unsaturated. Don't avoid fats, like protein and carbs, they have their place in our diets. One type of fat to avoid are trans fat, these are basically artificial fats. They won't be listed on the back of food packaging, however it should be under the ingredients as "hydrogenated palm oil" or "hydrogenated oil". Unlike other fats, no amount of trans fats are recommended. The National Academy of Sciences states: "Trans fatty acids are not essential and provide no known benefit to human health".

I believe that when a runner should eat is down to individual's needs and should be discovered through trial and error. However, if you are a morning runner, you may notice a sluggish performance before breakfast. This is due to low blood sugar levels. To overcome this, you should eat a little something before running (such as a slice of toast). Eating so little so close to running should be ok if you are training at training pace. Preferably, your workout should be timed to finish just before lunch or dinner. If you run after lunch or dinner, it may take anything from 1 to 3 hours for your food to digest. I recommend leaving 1 hour between drinking and then running, and 2 hours between eating and running. If you are doing speedwork, longer may be necessary. Beginner runners should not be running at distances where 'in-run' fueling is required.

A balanced diet should provide you with all the minerals and vitamins you require. If for some reason you do not eat a balanced diet, suppliments may be required. This is especially true of vegetarians, who will miss out on the elements that meat and fish provide. Women runners may need to take iron tablets more than men due to menstruation, iron is required for the production of hemoglobin - the part of red blood cells which carries oxygen.

If you are running to lose weight, you have made a good choice. But whatever you do, always exercise whilst dieting. Muscle burns calories, and if you do not exercise whilst loosing weight, you will lose muscle as well as fat. This means that the next time you come around to dieting it will be much harder, because there is not as much muscle to burn energy. This is called the 'yo-yo' effect. If you lose weight once however, and do everything correctly, you should not need to diet again. A diet is not short term, it is a long term lifestyle change. Running is the best exercise in terms of time to do to lose weight. You will burn around 100 kcal for every mile you run, speed is not a factor in this, even if you walked the mile, you would still burn 100 kcal - but it would take much longer. Compare this to cycling, where you may have to ride several miles to equal 1 running mile in terms of energy burned. (In terms of a workout and fitness, 1 running mile equates to 4 miles cycling).

Men should eat 2500 kcal a day, and women 2000. The basic principle of losing weight is to eat less than you burn. Most experts recommend losing no more than 1-2 pounds a week. 1 pound is 3500 kcal. Ideally, you should burn 500 kcal a day more than you eat when losing weight. There are no quick fixes but some diets claim that you can lose pounds of fat in days, out-of-shape beginners are taken in by these claims on a false assumption. These diets work on the body in cirtain ways that mean you are not losing fat. For instance, if you just ate foods with little salt, your muscles would lose fluid, and you would lose weight - but it would not be fat, (salt retains fluid). Running and exercise in general does wonders for your metabolism. You can continue to burn calories at a faster rate hours after exercise, and the muscle you build from running will also help you burn more calories. This is because muscle needs 10x more energy to maintain itself than fat. One thing that dieters should not do is skip breakfast. If you do this, your body will burn calories more efficantly (thus slower) because it believes you are in a situation where energy is sparse (this is an evolutionary mechanism).

Other things you could do to lose weight are begin weight training to build more muscle, avoid snacking, and basically follow your instinct and common sense. Losing weight is very difficult and you must find the motivation within yourself. Women need not worry about looking bulky from running or weight training, as their female hormones don't allow a man's physique. Whether you are looking to eat healthier or to lose weight, good luck. Remember it may have taken years for you to get out of shape, it will take just as long to get back into it.