I am not an expert in the science of sport nutrition, but sometimes I need to point people in the direction that I believe is beneficial for them. It is actually hard to find information that does not have some sort of weird twist to it.
I like the sound of these 7 bullet points...
Sports Performance Bulletin nutritional expert, Charles Remington, explains the health problems you may experience with a low carbohydrate diet. (http://www.pponline.co.uk)
1. Poor exercise performance and recovery
Carbohydrates are the primary fuel for your muscles and brain. Eating a low carbohydrate diet prevents proper maintenance of muscle and liver glycogen (storage form of carbohydrate and water), thus decreasing muscle performance and increasing muscle fatigue. ATP is the main source of energy for all muscle contractions. When a muscle is used, a chemical reaction breaks down ATP to produce energy. There is only enough ATP stored in the muscle for a few contractions. More ATP is needed. There are three enzyme systems that can create more ATP. The three sources of ATP for muscle contractions are carbohydrates, fatty acids and amino acid proteins. Carbohydrates metabolize efficiently and are therefore used first. If carbohydrates are not available, your muscles metabolize fatty acids and amino acids as secondary sources of ATP. These secondary sources are not efficient, which consequently cause your strength and endurance to drop drastically. It needs to be customized to your amount of muscle and exercise schedule. High-fibre, low-glycemic (turn into blood sugar slowly) carbohydrates can provide up to 50% of your calories, which will lead to increases in strength and muscle endurance.
2. Gout
Gout is a form of arthritis that occurs when excessive uric acid levels start to crystallize in joints, leading to pain and inflammation. Uric acid is a waste product in the liver's metabolism of protein. Excessive amounts of protein may lead to an inability to eliminate uric acid. I would recommend you should not exceed 1 to 1.25 grams of protein per lean pound of body weight.
3. Kidney stones
Kidney stones are hard masses that form in the kidneys when uric acid or calcium oxalate crystallize and over time form stones. Insoluble fibre, found only in carbohydrates reduces the absorption of calcium, which cause urinary calcium levels to drop thereby preventing the formation of kidney stone. I would recommend the consumption of 30 or more grams of fibre daily. This is not attainable on low carbohydrate diets.
4. Constipation and poor intestinal health
To maintain good intestinal health our bodies require 30 or more grams of fibre daily. Fibre is divided into two types, soluble and insoluble. Insoluble fibre is vital in formation of stools and decreases the time process of waste elimination. Low carbohydrate diets are too low in insoluble fibre and increase risk of constipation. Poor transit time of waste material increases risk of certain colon cancers. Insoluble fibres prevent the build-up of mucus on intestinal walls which lead to poor absorption of nutrients into the body. Low carbohydrate diets are inadequate to maintain good intestinal wall health. I would recommend you use whole grains, oats, beans, fruits and vegetable which are rich in soluble and insoluble fibre. This lowers the risk for constipation, hemorrhoids, irritable bowel, diverticulitis, Crohn's disease, and colon cancers.
5. Rise in cholesterol levels and an increased risk of heart disease
The risk of heart disease increases on low carbohydrate, low fibre diets. These diets promote excessive amounts of animal protein, cholesterol and saturated fat. Exuberant amounts of protein increase homocysteine, which is a by-product of the amino acid methionine. Many experts believe that high homocysteine levels have many toxic effects which lead to increase risk of heart disease and hardening of the arteries. Low carbohydrate, low fibre diets reduce the absorption and elimination of digestive bile in the intestines. Digestive bile is produced in the liver from cholesterol. A decrease in digestive bile production raises blood serum cholesterol levels which increases the risk of heart disease. Unlike low carbohydrate diets I would promote a nutritional balance providing 30% protein, 50% high fibre carbohydrates and 20% fat.
6. Osteoporosis
Osteoporosis is the reduction of bone density, due to the loss of calcium over long periods of time. Several dietary factors increase the risk of osteoporosis. When dietary protein reaches excessive levels, so does the loss of calcium in the urine. Most studies show that a life-long high protein diet results in an increase of obsteoporosis. Poor intestinal health due to low fibre diets cause inadequate absorption of calcium in intestines contributing to poor bone formation. This would suggest that no low carbohydrate diets can become a life long lifestyle of eating. This is only one of many reasons why low carbohydrate diets provide poor long term weight control. Interestingly, a diet too low in protein can also increase risk of osteoporosis. There is no one size fits all when managing our weight so it has to be customized to the individual, providing the right balance of protein, carbohydrate and fat.
7. Loss of muscle and reduction of metabolism
Any diet that applies the restriction of calories less than the body's daily requirements over long periods of time will result in the loss of lean muscle tissue and a decrease in the metabolism. All low carbohydrate diets are focused solely on weight loss. The loss of fat comes at a high cost, which is the loss of lean muscle. The loss of muscle reduces the resting metabolic rate, which is the major cause for rebound weight gain. Research shows 95% of all dieters will regain that weight . We do not fail at diets - diets fail us! The secret is not to try to lose fat every day as this will result in losing muscle and reducing metabolism.
What do you think? Doesn't sound like low-carb diets have much benefit?!
Tommi
PS: Food is an important part of a balanced diet.
Fran Lebowitz
