Low-Carb-Diet

Popular Diets Reviewed:

Do Low-Carb-Diets make the grade?

• Introduction
• Why this diet?
• Pros
• Cons
• Make the Grade?
• References

Introduction: Grading Low-Carb-Diets

A low carbohydrate, or low-carb-diet can help control blood sugar, and is used to help with weight loss, blood pressure control, and blood cholesterol control. There are several popular low-carb diets, such as the Atkins, South Beach, and Zone diet. When total carbs are reduced, people eat larger proportions of protein and fat. Some low-carb diets recommend replacing carbohydrate with healthful sources of protein and fat; others, such as the Atkins-Diet, do not restrict any type of protein or fat sources. You may find that generally eating fewer carbs may be beneficial, without having to follow a specific program.

• The standard diet generally referenced by dietitians provides 2,000 calories, with about 60% of these coming from carbohydrates, which means about 300 grams of carbohydrate per day. Anything less than this could be considered a low-carbohydrate diet. Popular low-carb diets range from almost zero carbs to about 35% (about 175 grams per day).

• Dieters are cautioned against eating less than the Recommended Dietary Allowance of 130 grams of carbohydrates per day (26% of calories in a standard diet).

• Keep in mind that your personal requirements might be more or less than 2,000 calories.

 Take a low-carb-diet for a test drive:

 

Why do people follow this diet?

Many people expect to have better success with weight loss and control of blood pressure, blood sugar, and blood cholesterol levels by following a low-carb-diet.

Some specific low-carb-diet programs, such as the Atkins-Diet, restrict carbohydrate to the point that the body breaks down fats into ketones, which can either be used either as energy or eliminated from the body via the breath or urine. Diets such as the South Beach and the Zone diets are less restrictive, and some, such as Sugar Busters, seek to eliminate only sugars and high-glycemic-index foods that excessively raise blood sugar.

What do the advocates say?

Advocates contend that the high amount of carbohydrates in typical modern diets is unnatural for humans, who evolved for hundreds of thousands of years while eating a low-carb-diet. They say that the current over consumption of carbs has led to increasing problems with obesity, diabetes, and other health problems. High-carbohydrate diets are presumed to result in higher insulin levels, which may lead to insulin resistance and related metabolic disorders such as high triglycerides, low HDL ("good") cholesterol, and high blood pressure.

Some scientific authorities do recommend that people with the insulin resistance syndrome (IRS) or type 2 diabetes avoid high-carbohydrate diets, and some recommend a diet lower in carbohydrate than current public health guidelines suggest.

Researchers have demonstrated that replacing carbohydrate in the diet with either fat or protein lowers blood triglycerides and raises HDL ("good") cholesterol, and a few studies have also reported improved blood sugar control and increased loss of weight and body fat resulting from these dietary changes.

What do the critics say?

Many nutrition experts disagree with the basic premise of low-carb-diets—the notion that high-carbohydrate, low-fat diets cause obesity and other health problems. In one argument, some nutritionists point to the traditional Japanese diet that is very high in carbohydrates, low in protein, and very low in fat, yet is associated with good health and normal weight in people who follow that diet. Rather than attributing obesity and other problems to carbohydrate intake, these critics blame the overconsumption of calories (from any source) and lack of physical activity as the primary causes of these health disorders.

Critics concede that low-carb-dieters often experience significant weight loss during the initial stages of the diet. However, these critics argue that these diets often have a diuretic effect (in other words, they promote water loss) and that the initial weight loss is due to water loss, not fat loss. Recent research suggests that some people may lose more weight over the course of several months on a low-carbohydrate diet than on one that is equal in calories but higher in carbohydrates, but few studies have been done to determine the long-term effects, good or bad, of low-carbohydrate diets.

In addition, many authorities are concerned that a lower-carbohydrate diet may result in higher calorie intake from fat, which could lead to more difficulties with overweight, insulin resistance, high cholesterol levels, and heart disease risk. Studies of low-carbohydrate diets that are also low in calories and promote weight loss often do not support these concerns, but research on the effects of higher calorie versions of these diets is scarce and conflicting. Increased protein intake as a result of avoiding carbohydrates is also a concern for some critics, since some high-protein diets may increase the risk of osteoporosis, kidney stones, and some cancers.

Critics also express concern that the lack of grains, fruits, and vegetables in low-carbohydrate diets may lead to deficiencies of key nutrients, including fiber, vitamin C, folic acid, and several minerals.

Best food choices if being selective on a Low-Carb-Diet

The human body works best with a diet that includes some carbohydrate. Recently a Recommended Dietary Allowance for carbohydrate was set at a minimum of 130 grams per day. This would represent 26% of the calories in a 2,000-calorie-per-day diet, which would still be considered a low-carbohydrate diet, but would avoid the potential hazards of more restrictive diets, including symptoms of ketosis (nausea, weakness, dehydration, light-headedness, and irritability) and loss of body protein.

Certain dietary fats and their food sources are associated with good health and reduction of disease risks. Foods high in unsaturated fats that are free of trans fatty acids have been associated with protection from atherosclerosis, heart disease, insulin resistance, and other health concerns. Examples of these foods include olive oil, fatty fish, flaxseeds, and nuts. However, replacing high-carbohydrate foods with these foods may increase calorie intake if portion sizes are not kept moderate.

Certain sources of dietary protein are more healthful than others. Protein foods containing significant amounts of saturated fat and cholesterol have been associated with many diseases, including heart attacks, type 2 diabetes, insulin resistance, and gallstones; choosing low-fat and low-saturated-fat protein foods can minimize these risks. High meat intake, even of leaner cuts, may increase risk of osteoporosis and kidney stones. Well-done meat or meat that has been preserved with nitrites should be avoided, or kept to a minimum, due to links with cancer. The most healthful choices for increasing protein intake are fish and seafood, low- or nonfat dairy products, legumes (including soyfoods), nuts, and seeds.

Even a low-carbohydrate diet should emphasize healthful carbohydrate sources. Whole grains, fruits, and vegetables supply fiber and many important micronutrients. People with diabetes or insulin resistance may find that choosing carbohydrate foods with a low-glycemic index improves their blood sugar, blood cholesterol, and triglycerides; helps them better control their weight; and improves symptoms associated with their health conditions.

Bread, cereal, rice, and pasta

• Whole wheat and whole grain breads
• Breads containing whole, intact grains and seeds (millet, flaxseed, etc)
• Whole wheat pasta and noodles
• Brown rice, basmati rice
• Barley, buckwheat
• Whole grain cereals, muesli
• Whole wheat pita, whole grain wraps
• Oatmeal

Dairy products and dairy substitutes

• Nonfat milk and milk products
• Unsweetened nonfat yogurt
• Soy beverages

Fats and oils

• Non-hydrogenated olive oil, canola oil, peanut oil
• Non-hydrogenated corn oil, flaxseed oil, hemp oil, pumpkin seed oil, safflower oil, sesame oil, soybean oil, sunflower oil

Protein (meat, poultry, fish, eggs, nuts, and beans)

• Lean chicken and turkey
• Egg whites
• Seafood and fish
• Dried beans and peas
• Soy foods
• Nuts and seeds

Do low-carb-diets make the grade?

My-Nutrition-Coach’s opinion regarding low-carb-diets:

Many dieters that are also exercising while following a low-carb-diet may find that this meal plan may not provide enough energy to fuel their muscles and support their activity level.  We also share the same concerns as other nutrition critics of low-carb-diets that this type of diet may be restricting valuable vitamins and minerals and not providing complete balanced nutrition.

Suggestion: Create a well-balanced weight loss plan that controls calories every day, includes exercise, and allows a wide variety of healthy foods. To lose weight, it is simply not enough to restrict just one type of macronutrient without addressing eating habits that cause weight gain.  Take a look at our review of Mediterranean diets for a diet that gets better grades or try the Ultimate Meal Plan Project in our online meal planner to instantly create meal templates that get all A's

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References for low-carb-diets:

Bravata DM, Sanders L, Huang J, et al. Efficacy and safety of low-carbohydrate diets: a systematic review. JAMA 2003;289:1837–50 [review].

Brehm BJ, Seeley RJ, Daniels SR, D'Alessio DA. A randomized trial comparing a very low carbohydrate diet and a calorie-restricted low fat diet on body weight and cardiovascular risk factors in healthy women. J Clin Endocrinol Metab 2003;88:1617–23.

Kennedy ET, Bowman SA, Spence JT, et al. Popular diets: correlation to health, nutrition, and obesity. J Am Diet Assoc 2001;101:411–20 [review].

Malik VS, Hu FB. Popular weight-loss diets: from evidence to practice. Nat Clin Pract Cardiovasc Med 2007;4:34–41.

Meckling KA, Gauthier M, Grubb R, Sanford J. Effects of a hypocaloric, low-carbohydrate diet on weight loss, blood lipids, blood pressure, glucose tolerance, and body composition in free-living overweight women. Can J Physiol Pharmacol 2002;80:1095–105.

Reaven GM. Do high carbohydrate diets prevent the development or attenuate the manifestations (or both) of syndrome X? A viewpoint strongly against. Curr Opin Lipidol 1997;8:23–7 [review].

Stein, K. High-protein, low-carbohydrate diets: Do they work? J Am Diet Assoc 2000;100:760–1.

Fleming RM. The effect of high-protein diets on coronary blood flow. Angiology 2000;51:817–26.

Sondike SB, Copperman N, Jacobson MS. Effects of a low-carbohydrate diet on weight loss and cardiovascular risk factor in overweight adolescents. J Pediatr 2003;142:253–8.

Westman EC, Yancy WS, Edman JS, et al. Effect of 6-month adherence to a very low carbohydrate diet program. Am J Med 2002;113:30–6.