Carbohydrate
low and high diet, benefit and harm
June 24 2017 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.
It is okay to consume carbs as long as the amount is not too high
per meal and you engage in some physical activity during the day. Eating
a high carbohydrate meal can make you sleepy.
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).
Athletic performance
Swishing a sports
drink in the mouth and swallowing may give athletes a little boost.
Cancer risk
People who eat more highly processed foods such as mass processed
packaged bread and baked goods, sodas and sweetened drinks, and instant
noodles have a higher risk of cancer. It’s long been known that eating
fresh fruits and vegetables and whole grains lowers the risk of cancer.
Highly-processed foods carry an extra risk of cancer.
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.
Vision
loss
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.
Carbohydrate list
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 carbohydrate
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.
questions
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.