Low carbohydrate diets: good or bad?
During the days of fad diets, there are many different ways people try and lose weight. No matter what method you choose, the basic principle behind any diet is to expend more calories than you consume.
One particular diet that has been very exposed and used is the Atkins diet, which is a diet that almost eliminates your intake of carbohydrates but allows you to eat as much protein or fat as you’d like. The idea behind these types of diets is that carbohydrates are the major food source and typically the main component of mixed meals. By eliminating carbohydrates, you are removing a large percentage of daily caloric intakes and reducing the overall amount of calories but also eliminating the major source of energy for your muscles.
Note: There are many different nutrients that are required in a healthy diet and this article’s focus is strictly on ‘carbohydrate diets’ and their effects, both positive and negative, on different populations.
Results were drawn from studying 3 separate populations; obese/sedentary people, body-weight-stable people who are physically active, and athletes. Each population was examined in a different study with similar parameters as far as the diet is concerned. First, we will look at the obese population.
Two similar studies were conducted in the obese population (35-50% body fat,) randomly assigning individuals to one of two different diets. Group one was a low-carbohydrate diet which is unrestricted in total calories and group two was a conventional diet, low in fat with a restricted caloric intake different for men and women. Group one showed a larger decrease in body fat percentage over group two (8% compared to 4%) within the first three months. Between the three and six month time frame, both groups weight loss hit a plateau. From that time to the one year mark, there was an increase in weight, more-so in the group of low-carbohydrate diets. On the negative side, low-carbohydrate diets have been show to increase LDL-cholesterol and the low amount of vegetables, fruits and fiber consumed has a potential to increase the risk of coronary heart disease.
A similar study was conducted in body-weight-stable individuals who are physically active. Again, one group consumed 15% of total calories from carbohydrates and another 65% over a seven week period where they performed endurance training 3-4 times per week. This study concluded that a low-carbohydrate diet during an endurance training program is detrimental to improvement in endurance where the high-carbohydrate diet made intense exercise less difficult to maintain.
A third study looked at competitive, lean athletes. Results showed that a low carbohydrate diet may help reduce total body fat, but also can cause a loss of muscle mass and could lead to overtraining which can be detrimental to an athlete’s career. A high-carbohydrate diet, although doesn’t help reduce body fat, will help increase performance and decrease overtraining.
The rational for the second two populations is this: After very hard exercise such as encountered in playing soccer, basketball or tennis intensely for 30-90 minutes, at the very least, about 24 hours is needed to replenish muscle glycogen. To replenish glycogen in this short time period, a diet must contain the proper amount of carbohydrates, along with other nutrients such as protein. Although a low-carbohydrate diet would provide the necessary amount of protein, it does not allow intake of the required nutrients from carbohydrates in order to fully recover from exercise.
For most people, the main goal of starting a diet is to lose weight. While initially these low-carbohydrate diets are an effective way of achieving this goal, most results are short term and can produce negative effects on overall health which is a result of increased fat consumption. The disadvantages associated with these diets; decrease in lean tissue, fat loss not being maintained after 1 year, low intake of healthy fruits and vegetables and an increase in LDL-cholesterol, severely outweighs the advantages. Instead, a balanced diet that limits the amount of fat as well as total calories is the best way to go. The loss of body fat will not be as much at the start, but over a period of time, it is similar to that of the low-carbohydrate diets. It also helps in preserving lean muscle mass. This is especially important for athletes or any individual who exercises. After an exercise session, your muscles are depleted of glycogen, or sugar stores which is used for muscle contractions. In order to properly replenish these stores for your session, carbohydrates are needed. Since everyone has different levels of daily activity, it is recommended to see a registered dietitian in order to receive a personalized diet, but this article offers general guidelines on carbohydrate ingestion for optimal recovery after exercise.
For further information or more details about the studies and their results, follow the link to access this article! Highs and Lows of Carbohydrate Diets
by Matt Percia