Carbohydrates are the body's main fuel source and should therefore make up the majority of your daily energy intake, mainly in the form of whole grains, vegetables, legumes and some fruit. Exactly how many carbohydrates you need depends on a number of factors, but intake should make up between 40 and 60 percent of total calories.

Factors that influence your recommended carbohydrate intake include:

• Body weight. More specifically, the amount of muscle. The greater your muscle mass, the more carbohydrates you need.
• Gender. Males generally require more carbohydrates because of their greater muscle mass.
• Training level. Elite athletes will have greater needs than a recreational athlete who goes to the gym three times a week. The more active you are, the more carbohydrates you will need.
• Type of sport. Endurance-type sports, such as long distance running, require more carbohydrates than “short-energy burst”’ sports, such as a 100 meter sprint. Any aerobic sport also requires substantial stores of carbohydrates.
• Diabetes. Although most people with diabetes can include a moderate amount of carbohydrates in their diet, individual health will affect particular dietary needs.
• Carbohydrate-sensitivity, grain allergies, digestive disorders. If you have any of these conditions, you may only be able to include a gradual and moderate amount of selective carbohydrates in your diet.

* You should discuss your recommended calorie and carbohydrate intake with your doctor or dietitian.

From The CalorieKing Calorie, Fat and Carbohydrate Counter, 2008 Edition, page 8.

There is so much confusion over the issue of whether or not carbohydrates are fattening! Some people say not to eat pasta, bread or potatoes because they are fattening, but then others say that you should eat more carbohydrates because they are good for you. The truth is that carbohydrates are an essential part of any diet. However, too much of anything, including carbohydrates, can be fattening. It is best to develop a good understanding of how many carbohydrates you need so as to be sure you don’t eat too many or too few. Here are some points to keep in mind when considering the relationship between carbohydrates and weight loss:

• "No carbs" means no real weight loss. When you don’t eat carbohydrates you break down muscle tissue along with body fat. If you lose weight as a result of this, you also lose your muscle. When you start putting carbohydrates back into your diet, you quickly gain the weight back.
• Food is a complex mixture of many nutrients, so it is impossible to say that just one type of food is fattening. The nutrients which provide energy are carbohydrates, fats, and proteins, and most foods contain all of them. This energy is measured in calories or kilojoules. (Alcohol also provides energy, but in the form of "empty" calories as it has no nutritional value).
  

As indicated by the chart, different nutrients contribute a different amount of calories. Fats provide more than twice as many calories as carbohydrates.

• We usually eat carbohydrates and fat together. For example, a pasta meal can consist of spaghetti in an oil-based meat sauce topped with cheese. These ingredients contain a lot of fat and therefore contribute many calories. Pasta alone contains very little fat and mainly consists of carbohydrates, which contribute fewer calories. This pasta meal is fattening more because of the sauce than the pasta.

• Too much of anything is fattening! If you eat too much of anything, it’s going to add excess weight. As a recent WHO (World Health Organization) report points out: "It is important to state that excess energy (calories) in any form will promote body fat accumulation and that excess consumption of low fat foods, while not as obesity-producing as excess consumption of high fat foods, will lead to obesity if energy expenditure (exercise) is not increased." When more carbohydrates are eaten than is good for the body, most of it is stored in the liver and muscles as glycogen; the remainder is stored as fat.

• Carbohydrates are more filling than fat. The fiber content of most carbohydrates swells in the digestive system which makes us feel full faster than other foods do. Also, the conversion of dietary fat to body fat requires very little energy compared to carbohydrate conversion; in fact, only 3% of energy intake is required in this process. Compared to carbohydrates, it can be easy to eat too much fat because foods high in fat are generally low in dietary fiber, and therefore it takes more of these foods for us to feel full.