Carbohydrate low and high diet, benefit and harm, by Ray Sahelian, M.D.
There are many types of different carbohydrates -- fiber, sugar and starch -- and they each affect your body differently. Types of common foods high in carbohydrate include bread, pasta, potatoes, grains, and fruits. A carbohydrate food that has a high glycemic index usually has a great amount of simple sugars and little or no fiber while foods that have a low amount of sugar and a lot of fiber have a low glycemic index.
Carbohydrate turns to fat
Trimming carbohydrate intake results in healthy improvements in blood fat levels, even if a person doesn't lose an ounce. Carbohydrates, especially simple sugars, can cause unhealthy changes in blood fats by causing fat to collect in the liver -- just as it does on one's thighs or belly. These fats eventually find their way into the bloodstream. Cutting down on these fat deposits by cutting carbohydrates reduces fat levels in the blood, and may also boost the body's ability to break down fats that do reach the bloodstream.
Types of carbohydrates
Carbohydrates can be divided into three main groups, sugars, oligosaccharides (short-chain carbohydrates), and polysaccharides (long-chain carbohydrates).
Swishing a sports drink in the mouth and swallowing may give athletes a little boost.
Heart disease risk
Women who eat more white bread, white rice, pizza, and other high glycemic carbohydrate-rich foods that cause blood sugar to spike are more than twice as likely to develop heart disease than women who eat less of those foods. Men who eat lots of those carbohydrates -- which have what's known as a high glycemic index -- do not as much of an increased risk, however, perhaps because their bodies process the carbs differently. The study author is Sabina Sieri, of the Fondazione IRCCS Istituto Nazionale dei Tumori, a national institute for cancer research in Milan, Italy. April 2010.
People who cut out saturated fatty acids while increasing their intake of white bread, pasta and other refined carbohydrates that can cause blood sugar to spike are likely to increase their risk for heart disease. American Journal of Clinical Nutrition, April 7, 2010.
Carbohydrate and sleep
High-glycemic-index carbohydrate meals shorten sleep onset. American Journal of Clinical Nutrition, Vol. 85, No. 2, 426-430, February 2007. Ahmad Afaghi, Helen O'Connor and Chin Moi Chow. From the School of Exercise and Sport Science, Faculty of Health Sciences, The University of Sydney, Sydney, Australia
To investigate the role of carbohydrate in sleep induction, we explored the effect of glycemic index (GI) and meal time on sleep in healthy volunteers. We compared the effect of high- and low-GI carbohydrate –based meals ingested 4 hours before bedtime on sleep quality. We also evaluated the effect of the timing of high-GI meals (4 h compared with 1 h) on sleep quality. Twelve healthy men (aged 18-35 y) were administered standard, isocaloric (3212 kJ; 8% of energy as protein, 1.6% of energy as fat, and 90% of energy as carbohydrate) meals of either Mahatma (low GI = 50) or Jasmine (high GI = 109) rice 4 h before their usual bedtime. On another occasion, the high-GI meal was given 1 h before bedtime. A significant reduction in the mean sleep onset latency (SOL) was observed with a high-GI compared with a low-GI meal consumed 4 h before bedtime. The high-GI meal given 4 h before bedtime showed a significantly shortened SOL compared with the same meal given 1 h before bedtime. No effects on other sleep variables were observed. We showed that a carbohydrate-based high-GI meal resulted in a significant shortening of SOL in healthy sleepers compared with a low-GI meal and was most effective when consumed 4 h before bedtime.
The carbohydrates present in a diet can influence the risk of age-related macular degeneration (AMD), the most common cause of vision loss in older adults. Dr. Allen Taylor, of Tufts University, Boston conducted a study of 4,099 participants, aged 55 to 80 years, in the Age-Related Eye Disease Study. Regular consumption of a diet with a high-glycemic index - a diet containing carbohydrates that quickly raise blood sugar levels -- significantly increased the risk of AMD relative to regular consumption of a diet with a low-glycemic index. American Journal of Clinical Nutrition, July 2007.
Carbohydrates are classified as simple or complex. The classification depends on the chemical structure of the particular food source and reflects how quickly the sugar is digested and absorbed. Simple carbohydrates have one (single) or two (double) sugars while complex carbohydrates have three or more sugar molecules attached to each other.
Examples of single sugars from foods include:
Fructose found in fruits - The consumption of fructose, primarily from high-fructose corn syrup (HFCS), has increased considerably. Fructose is a potent reducing sugar that promotes the formation of toxic advanced glycation end-products, which appear to play a role in the aging process; in the pathogenesis of the vascular, renal, and ocular complications of diabetes; and in the development of atherosclerosis.
Galactose found in milk products
Double sugars include:
Lactose found in milk and dairy product
Maltose found in certain vegetables and in beer
Sucrose (table sugar). Honey is also a double sugar, but unlike table sugar, contains a small amount of vitamins and minerals.
Complex carbohydrates, often referred to as "starchy" foods, include:
Whole grain breads and cereals
Starchy vegetables such as potato and yam
Legumes such as beans and peas
Simple carbohydrates are also found in processed and refined sugars such as candy, table sugar, syrups (not including natural syrups such as maple, and regular carbonated beverages.
Low carbohydrate diet
Low-carbohydrate diets are based on an alternative theory of obesity where dietary carbohydrate, particularly unprocessed sugars, causes hyperinsulinemia, leading to insulin resistance, obesity, and cardiovascular disease. In this model, carbohydrate is viewed as a "metabolic poison" and therefore is limited in the diet. With over 60% of the population being overweight, physicians face a major challenge in assisting patients in the process of weight loss and weight-loss maintenance. Low-calorie diets can lower total body weight by an average of 8% in the short term. These diets are well-tolerated and characterize successful strategies in maintaining significant weight loss over a 5-year period. Very-low-calorie diets produce a more rapid weight loss but should only be used for fewer than 16 weeks because of clinical adverse effects. Diets that are severely restricted in carbohydrates (3%-10% of total energy intake) and do not emphasize a reduction of energy intake may be effective in reducing weight in the short term, but there is no evidence that they are sustainable or innocuous in the long term because their high saturated-fat content may cause clogged arteries. Fat restriction in a weight-loss regimen is beneficial, but the optimal percentage has yet to be determined.
Danger of Low Carbohydrate diet
Low carbohydrate, high protein diets may help to shed weight quickly but they can be unhealthy. These low carbohydrate diets can cause constipation, diarrhea, headache, bad breath and ketosis, which causes raised levels of ketones, or acids, in the body. In a case report, doctors at New York University School of Medicine said they had treated a 40-year-old obese woman, who had followed the Atkins diet, for a life-threatening illness known as ketoacidosis. The diet, based on research by Dr Robert Atkins who died in 2003, involves eating proteins such as meat and cheese and limiting carbohydrates such as bread and pasta. This patient had an underlying ketosis caused by the Atkins diet and developed severe ketoacidosis. Mild pancreatitis or stomach infection may have contributed to the problem. Ketoacidosis is caused by dangerously high levels of ketones in the blood. It can lead to coma and death if untreated.
Good carbohydrates are those foods high in fiber and having a low glycemic index. These are mostly complex carbohydrates found in unrefined cereals, beans, and peas.
One diet approach does not fit all patients. Some individuals might do best on a very-low-fat, high carbohydrate diet, whereas others may respond to lowering carbohydrate intake.
Carbohydrate counter - counting
Do you really need a carbohydrate counter or can you just use common sense and eat less sugar and simple carbohydrates rather than worrying and counting every carbohydrate in food that you come across.
The Foods You Eat May Be Affecting Your Sleep Habits By
Ray Sahelian, M.D.
Anyone who's gotten a little drowsy after Thanksgiving dinner knows that food can make you sleepy. But aside from overindulging, it's actually the type of food you eat that can influence how alert or sleepy you are. And one food in particular can send you off to dreamland, whether you're ready for bed or not. If you are in your energetic teens and 20s, different foods may not affect you as much. In youth, our brain chemicals are on full speed and whether we have pasta or protein for lunch may not influence how energetic we are the rest of the afternoon. But, as we get older, we are likely to notice the food-mood or food-sleepiness influence. Have you ever had a large lunch consisting of mostly pasta, such as spaghetti, and then had an irresistible urge to take a nap? I have long suspected, based on my personal observations, that the type of food we eat before bed influences sleep onset. Now, a new study confirms previous research that carbohydrates eaten before bed induce sleep. To investigate the role of carbohydrate in sleep induction, researchers at The University of Sydney in Australia compared the effect of high- and low-glycemic index (GI) carbohydrate-based meals ingested several hours before bedtime on sleep quality. Twelve healthy men ate standard, isocaloric (8% of energy as protein, 2% of energy as fat, and 90% of energy as carbohydrate) meals of either low GI or high GI rice four hours before their usual bedtime. On another occasion, the men ate the high-GI meal one hour before bedtime. The carbohydrate-based high-GI meal resulted in a significant shortening of sleep onset compared with a low-GI meal and was most effective when consumed four hours before bedtime. Although we don't normally advocate consuming carbohydrate, eating a higher proportion of carbohydrate while having very little fat and protein could be a boon to those have difficulty falling sleeping at night. Some options include pasta, potatoes, bread, cereal, and fruit salad. If you eat a large meal during the day that consists mostly of carbohydrate, you are likely to have difficulty concentrating or functioning at your best at work or at home. So, in order to stay alert during the day, stay away from carbohydrate. Instead, eat small, frequent meals with a higher proportion of protein and fat.
Q. I've been hearing a lot about glyconutrient lately, can you shed some light on this?
A. I have a full discussion on glyconutrients here.