|
Psychology Department |
Health Psychology Home PagePapers written by students providing scientific reviews of topics related to health and well being |
|
Home | Weight Loss | Alternative Therapy | Supplements | Eating Disorders | Fitness | Links | Self-Assessment | About this Page | |
Low-Carbohydrate Dieting: A solution to America’s Obesity Epidemic?
Alyson Mencio
20 September, 2006
The Facts
The obesity epidemic in the United States has become rampant. Nearly sixty-five percent of adults are over weight. At any given time, one-third of the population is trying to lose weight, while an additional one-third is trying to maintain their body weight (Kennedy, 2005). As a result, dieting, specifically low carbohydrate dieting, has been popularized, and become a national pastime in the United States. There are millions of websites dedicated to information about low-carbohydrate dieting on the Internet. The Low Carb Diet Tools website shown below (Table 1.1) is an interactive website that allows the user to search food categories the results are listed in ascending levels of carbohydrates within each category. This website also allows the user to search specific foods and their corresponding carbohydrate content.
Table 1.1 http://www.lowcarb.ca/low-carb-tools/carb_counter.html
What is Low-Carb? How does it Work?
While there is not an exact definition of a low-carbohydrate diet, each plan varies in reference to the authors, and low-carbohydrate diets are always being slightly altered as results and research become available. A good broad definition is that “low-carbohydrate diets restrict caloric intake by reducing the consumption of carbohydrates to between twenty and sixty grams per day—less that twenty percent of the daily caloric intake.” (Last, 2006). In general, consumption of meats—steak, ham, and bacon—increases, while consumption of fruits, vegetables, whole grains, and low-fat dairy decreases. Energy on low-carbohydrate diets comes primarily from saturated fats. Table 1.2 depicts the breakdown of caloric intake from carbohydrates, protein, and fat on various diet plans.
Nutritional and Caloric Assessment of Various Diets
|
Diet |
Total Calories per Day |
Carbohydrate grams per day (% of calories) |
Protein grams per day (% of calories) |
Fat grams per day (% of calories) |
|
Typical American diet |
2,200 |
275 (50) |
82.5 (15) |
85 (35) |
|
Low-Carbohydrate diet |
|
|
|
|
|
Atkins diet |
|
|
|
|
|
Induction phase |
1,152 |
13 (5) |
102 (35) |
75 (59) |
|
Ongoing phase |
1,627 |
35 (9) |
134 (33) |
105 (58) |
|
Maintenance phase |
1,990 |
95 (19) |
125 (25) |
114 (52) |
|
Moderate-carb diet |
|
|
|
|
|
Carb Addict’s diet |
1,476 |
87 (24) |
84 (23) |
89 (54) |
|
Low-Glycemic-index diet |
|
|
|
|
|
Sugar Busters! |
1,521 |
176 (46) |
89 (23) |
44 (26) |
|
Low-fat diet |
|
|
|
|
|
Weight Watchers |
1,462 |
207 (57) |
73 (20) |
42 (26) |
|
Very low-fat diet |
|
|
|
|
|
Ornish diet |
1,273 |
258 (81) |
48 (15) |
13 (9) |
Table 1.2 (Last, 2006)
What does the Research Say—Low Carb vs. Low Fat?
http://www.karatedepot.com/boxinggloves.html
A number of clinical trials have been done in attempts to answer this time-long question. In a randomized clinical trial published in the Diabetic Medicine Journal, one hundred and two patients with Type 2 diabetes were randomly recruited. The study was done over three months, and sought to examine and differentiate between the effects of restricting carbohydrates versus low fat dieting in obese subjects. Results showed that weight loss was greater in the low-carbohydrate group (-3.55kg vs. .92kg). However, saturated fat intake was significantly higher among those in the low-carbohydrate group. The results prove that carbohydrate restriction seems to be an effective method of achieving short-term weight loss (Daly, 2006).
Another randomized control trial done over a longer period of time yielded slightly different results. This particular study was done over one year. It involved sixty-three obese men and women who were randomly assigned to either a low-carbohydrate or low-fat group. Those on the low-carbohydrate plan lost significantly more weight at the three month and six month intervals (6.8% and 7% vs. 2.7% and 3.2%). However, “there were no significant differences between groups in percent weight loss at twelve months” (Volpe, 2006). The study also revealed that cholesterol increased among the subjects in the low-carbohydrate group. It was reported that for both groups, “adherence was poor, and attrition was high” (Volpe, 2006). In conclusion, more long-term trials are needed before any definitive conclusions and statements can be drawn (Volpe, 2006).
Thus far, research has indicated that low-carbohydrate dieting is more effective for short-term weight loss as compared to low-fat dieting. However, the long-term results show no differences in level of success between these two dieting programs.
Low-Carb Diets and Type 2 Diabetes
Obesity and Type 2 diabetes are directly related. Findings from a study showed that the characteristics of the person that is most likely to try a low-carbohydrate diet has the highest body mass index (BMI), more likely to be obese, have diabetes, have high blood pressure and increased cholesterol levels (Crowe, 2005).
One of the most prevalent theories about the carbohydrate-restricted diet is that it helps to modulate insulin levels. In effect, this restriction program helps to reduce the progression of Type 2 diabetes, which commonly associated with obesity. Carbohydrates break down into simple sugars during digestion. Obesity causes the body to become deficient in producing the amount of insulin secreted by the pancreas due to over use. Effectively, this leads to the onset of Type 2 diabetes. By restricting carbohydrates, the level of glucose in the blood is reduced, and the pancreas no longer has to overwork itself in the production of insulin to breakdown the body’s sugar (Kennedy, 2005).
Flaws in the Model
Currently, there is not enough evidence to determine if there are any serious health risks related to low-carbohydrate dieting plans. It should be noted that when restricting an entire food group, one’s body has a poor nutritional balance. While low-carbohydrate diets reduce calories they inevitable reduce nutrients as well (Kirby, 2006). Low-carbohydrate diets are generally low in potassium, fiber, calcium, iron, Vitamins A&E. This can lead to side effects such as diarrhea, constipation, headache, muscle cramps, increased menstrual bleeding and general weakness (Crowe, 2005). Carbohydrate-restricted dieting has a much lower rate of adherence, and higher rates of non-compliance.
The US National Weight Control Registry has conducted a longitudinal study evaluating the success of long-term weight loss with different dieting strategies. This department compiles details of individuals who have successfully lost more than 13 kg and have maintained their weight loss for a year or more. This study analyzed the weight loss strategies of 2681 members of the registry. Entry into the database is voluntary, and the registrants have to already have shed the excess pounds and kept them off. Less than 1% of these successful registrants followed a low-carbohydrate diet. These findings coupled with those listed above, suggest that this type of diet is not realistic for long-term weight loss success (Crowe, 2005).
Conclusion
The obesity epidemic has not ebbed because the public imagination believes that one can lose weight without reducing caloric intake and increasing physical activity to counteract caloric intake (Kennedy, 2005). “Approximately five percent of individuals who state that they are consuming a specific low carbohydrate diet are actually following that particular diet exactly” (Volpe, 2006). This statistic is indicative of poor compliance rate for this population.
It is important to keep in mind that the low-carbohydrate diet plans found on the Internet and at popular bookstores, like Atkins and South Beach, work best when complimented with physical activity. Maintaining weight loss is a change in lifestyle, and is most successful, the longer it is practiced. Therefore, diets should be tailored to the individual, and what they are able to make a personal commitment to. It seems the best solution to obesity in America is not restricted carbohydrate or low fat dieting, but to “eating wholesome foods, eating in moderation, and exercising regularly” (Kirby, 2006).
References
Baker, B. (2006). Weight Loss and Diet Plans: Several types of diet plans produce at least short-term weight loss; portion size may matter
more than what we eat. Lippincott Williams & Wilkins. Volume 106 Issue 6, 52-59.
Crowe, T.C. (2005). Safety of Low-Carbohydrate Diets. Obesity Reviews Volume 6 Issue 3, 235.
Daly, M.E., Paisey, R., Millward, B.A., Eccles, C., Williams, K., Hammersley, S. (2006). Short-term Effects of Severe Dietary Carbohydrate-restriction Advice in Type 2 Diabetes—a randomized controlled trial. Diabetic Medicine. Volume 23 Issue 1, 15.
Kennedy, R.L., Chokkalingam, K., Farshchi, R. (2005). Nutrition in Patients with Type 2 Diabetes: are low-carbohydrate diets effective, safe, or desirable? Diabetic Medicine. Volume 22 Issue 7, 821.
Kirby, R.K. (2006). Low-Carbohydrate Dieting. Volume 73 Issue 11.
Last, A.R., Wilson, S.A. (2006). Low-carbohydrate Diets. Volume 73 Issue 11.
Volpe, S.L. (2006). Popular Weight Reduction Diets. Lippincott Williams & Wilkins, Inc. Volume 21 Issue 1, 34-39.
Images
Last, A.R., Wilson, S.A. (2006). Low-carbohydrate Diets. Volume 73 Issue 11.
http://www.lowcarb.ca/low-carb-tools/carb_counter.html
http://www.amazon.com/gp/explorer/157954990X/2/ref=pd_lpo_ase/002-6311577-4029639?ie=UTF8
http://www.karatedepot.com/boxinggloves.html
**All images not cited under the picture**
Microsoft Office XP. (2001). Media Content Version 2002, Clip Art.
Psychology DepartmentThe Health
Psychology Home Page is produced and maintained by David Schlundt, PhD. |
 |
Vanderbilt Homepage | Introduction to Vanderbilt | Admissions | Colleges & Schools | Research Centers | News & Media Information | People at Vanderbilt | Libraries |Vanderbilt Register | Medical Center |
 Return
to the Health Psychology Home Page
|
 Send
E-mail comments or questions to Dr. Schlundt
|