In an attempt to become as healthy as possible, many runners overlook the simplest of advice regarding the food they consume - eat a variety of healthy foods and cover all food groups. High-carbohydrate diets are good for distance runners, but not at the expense of cutting out nutrients that come with protein and fat foods. Possibly the way to approach the situation is to have a well-balanced diet that will suit you when you are moderately active, then to attend to your additional caloric needs that are imposed on you during marathon training, add mostly carbohydrates to your normal diet.

Weight-loss diets are not advised when in marathon training; usually the added exercise will bring about the loss of some unneeded body tissue as time goes by. The greatest gift a person can self-impose is a healthy diet and regular exercise, hopefully not just during a time in training for a marathon.

Just as in the case of fluids, practice different approaches to your eating and running habits. Try different types and amounts of meals at different times before a long run or long race. Learn what settles on your stomach, and what minimizes the need to make a pit stop during a long run. Get well hydrated during the two days leading up to a marathon, but don't overdo it in the final hours before the race, or face the pit-stop problem. Ingesting carbohydrates leads to additional fluid retention, a desirable practice going into a marathon, and don't get concerned about weighing in a little heavy on the morning of race day - that's to be expected and is desirable.

Of all possible nutrition-related problems that can face an individual, probably the most common malady among distance runners is inadequate iron intake, a problem that is exaggerated when training in warm weather. Many runners, in an attempt to eat a more healthy diet, end up eliminating foods that provide iron - meat, dried fruit, eggs, to name some good sources. If you are getting the feeling that you are "dead-legged" during many of your runs, or if timed runs are getting slower or becoming more stressful at your normal pace, then it would be advisable to get your iron status checked. Actually, I strongly recommend getting a blood test when you are feeling in peak shape and all training is going well, because this gives you a reference point for any future time when not feeling so good.

Your body needs large quantities of energy to perform at your highest levels. Carbohydrates, fats and proteins are your only sources of food energy. Carbohydrates are simple and complex sugars. All sugars are reduced to glucose through the process of digestion. Glucose is then converted to glycogen so it can be metabolized by the muscle cells to develop energy. Humans store a limited supply of glycogen in the liver and in the muscles.

Running dramatically increases your body's needs for glycogen. Because glycogen is stored in limited quantities in your body, and because it is the preferred energy source for your body when you are running, dietitians recommend that carbohydrates should comprise 55 to 60% of your total energy intake. The best way to achieve this goal is by eating large quantities of foods that are rich in carbohydrates like: baked beans, breads, cakes, cereals, dried fruits, fresh fruits, honey, pancakes, pastries, potatoes, spaghetti, syrup, vegetables (legumes), and waffles. Fats are the most concentrated energy source, and comprise about 45% of the energy intake in a typical American diet. Eating such a large quantity of fat promotes excessive obesity and cardiovascular diseases such as arteriosclerosis.

Fats are abundant in virtually all animal by-products, and in vegetable oils, such as peanut oil, corn oil, cottonseed oil, and soybean oil. Dietary experts suggest that for better health, higher energy and better running, runners should reduce the fat in their diets to 30% of the total energy consumed.

Proteins are the building blocks of tissue, and as such, form a vital part of the nucleus and protoplasm of all cells. In addition, all enzymes found in the body are proteins. Running, even long distances, does not dramatically increase your protein needs. Dietary experts recommend that runners should consume about 15% of their total energy in the form of proteins. Common sources of protein are cereal, cheese, eggs, fish, lean meat, liver, low-fat milk, nuts, poultry, soya beans, brewers yeast, and vegetables.

The other key point to remember when you are trying to recover from exhaustive training in minimum time is that the most important meal is the first meal you eat after your workout is completed. Research has demonstrated that the first meal should be predominantly carbohydrate and begun within one hour of finishing training. Waiting just 2 hours after exercise to begin replenishing carbohydrate can lower the initial glycogen storage by 40 to 50% making it less likely that you will be able to fully recover your glycogen stores prior to your next training session.

This initial meal should consist of approximately a gram and half of carbohydrate for every gram of body weight. To find your weight in kilograms, divide your body weight by 2.2 pounds. For example: I weigh 160 pounds or 72.7 kilograms (160/2.2). Therefore, according to this research, I would need to consume about 109 grams (72.7 x 1.5) of carbohydrate in that initial meal, to properly begin replenishing my glycogen stores.

The main point I want you to grasp from this exercise is that good running requires a lot of carbohydrates, and if you are running a lot, you will need to make a maximum effort to consume enough carbohydrates. By this point it should be obvious to you that on the training weekends where you are running back to back long runs, you will need to severely restrict your fat intake and become a carbohydrate hog.

Federal Study on Diets concluded:

All effective diets produce results by reducing calories, increasing calorie consumption or some combination of the two strategies.

If you are concerned about lowering your cholesterol as well as losing weight, avoid the high protein diet and utilize the low fat diet, high carbohydrate diet. Diets that give the fastest weight loss, tend to put weight back on faster when you stop dieting.

The long term effectiveness of dieting is still undetermined, because most people return to their previous weight or a higher weight within a few months of terminating the diet.

Conclusion: To be effective over the long haul, a diet needs to incorporate a permanent lifestyle change.

Recent weight loss programs have focused on low carbohydrate diets. They are based on the belief that carbohydrates stimulate insulin release which increases hunger and fat deposition. There is much evidence to support this view.

In addition, type 2 diabetes mellitus can be viewed as exhaustion of the ability of the pancreas to release insulin in a person genetically predisposed by insulin resistance, i.e. persons who must produce more insulin to achieve control of blood sugar levels.

Not all carbohydrates are equal, however. Recent data suggests that persons who eat more whole grain foods and less refined carbohydrates may have a lower risk of developing overt diabetes (high blood sugar) even when genetically predisposed. In general, foods with a low glycemic index, meaning foods that produce a slower and lower rise in blood sugar, may help with weight loss, avoidance of high blood sugar and even prevention of overt diabetes mellitus type 2.

You might find the following site useful. http://www.diabetesnet.com/gi.html

I am not endorsing the book advertised on the page because I have not read it, but the list of foods is a start. You might find more comprehensive lists of the glycemic index of various foods by plugging "glycemic index" into your favorite search engine.