Low Carbohydrate Diets vs Low-Fat Diets - Research Paper Example

? Health Sciences and Medicine Low Carbohydrate Diets versus Low Fat Diets of the of the School/ This paper has investigated low carbohydrate diets in comparison with low fat diets, to determine their efficacy for weight loss and improved health outcomes. In overweight and severely obese individuals, there is increased risk of cardiovascular diseases, diabetes, hypertension, fatty liver disease, and other metabolic disorders. The evidence from research studies indicate that both types of diets are considered equally useful in reducing weight and lessening the related disease conditions. At the same time, some studies propose the use of low carbohydrate diets as more useful in reducing liver fats, and improving cardiac health and other disease conditions, as compared to the use of low fat diets. However, the researchers observe that longer term studies are required, to draw definitive conclusions in favor of low carbohydrate diets. Overall, it was found that achieving weight loss was the most important factor for eliminating metabolic disorders and diseases of vital organs threatening healthy living and longevity. It is concluded that both low carbohydrate diets and low fat diets are equally effective for losing weight. Thus, instead of resorting to drugs to address obesity and related health problems, it is recommended that either low carbohydrate or low fat diet, supported by exercise, should be adhered to over a long term for achieving sustained weight loss and improved health. Health Sciences and Medicine Low Carbohydrate Diets versus Low Fat Diets Introduction With the increasing prevalence of obesity over the last few decades, there is requirement for overweight patients and their health care practitioners to implement adequate measures on a continued basis, towards weight reduction and prevention of related diseases such as hypertension, diabetes, cardiovascular disease, and other metabolic disorders. “Fewer than 25% of Americans who attempt to lose weight actually reduce caloric intake and increase exercise as currently recommended” (Yancy et al., 2004, p. 769). Further, after achieving weight loss, most people face a long term combat against the regaining of lost weight. Thus, several billions are expended annually on weight loss products and services (Yancy et al., 2004). Most weight loss interventions are not evidence-based; hence practitioners frequently lack the information required to recommend a particular therapy, or to supervise a patient who is administered a selected type of treatment (Yancy et al., 2004). Although low fat diets are generally recommended for obese individuals to achieve weight loss that is sustained in the long term, low carbohydrate diets also are extensively used for the purpose (Nordmann et al., 2006). Hence, low carbohydrate diets and low fat diets have been examined by researchers to decide on their efficacy for weight loss and improved health. Thesis Statement: The purpose of this paper is to compare low carbohydrate diets with low fat diets, and to examine the weight loss and health outcomes of both types of diets. Comparison of Low Carbohydrate Diets with Low Fat Diets Overweight and obese conditions are precursors of metabolic syndrome characterized by abnormal distribution of plasma fatty acids and increased inflammation, dyslipidemia and glycemia. Forsythe, Phinney, Fernandez et al. (2008) investigated the use of a low carbohydrate diet on the components of metabolic syndrome. They found that “a very low carbohydrate diet resulted in profound alterations in fatty acid composition and reduced inflammation compared to a low fat diet” (Forsythe et al., 2008, p. 65). The NHR (2011) observed that limiting carbohydrates, and not calories help to reduce liver fats more rapidly. This is supported by NHR (2010) who state that low carbohydrate diets burn more excess liver fat than low calorie diets. USA Today (2010) reiterate that low carbohydrate diets burn more fat than low calorie diets. The reason is that for people on low carbohydrate diets there is greater dependence on the oxidation of fat in the liver for energy, than for those on low calorie diets (USA Today). A study conducted by the South Western Medical Center, Dallas, found that after 2 weeks, the average weight loss experienced by the low carbohydrate dieters was 9.5 pounds, while that of the low calorie dieters was 5 pounds (USA Today, 2010). A meta-analysis of randomized controlled trials was conducted by Nordmann et al. (2006). The researchers have found that low carbohydrate diets were more useful than low fat diets in leading to weight loss after 6 months, however reduction in weight was not found after 12 months of follow-up (Nordmann et al., 2006). In relation to cardiovascular risk factors as well as changes in blood pressure, both low carbohydrate and low fat diets had similar benefits (Nordmann et al., 2006). As compared to the low carbohydrate group, the low fat group lost more low density lipoprotein cholestrol (LDL-C) (Nordmann et al., 2006). On the other hand, the low carbohydrate group experienced a more beneficial change in “high density lipoprotein cholesterol (HDL-C) and triglyceride values” (Nordmann et al., 2006, p. 292). Nordmann et al. (2006) consider the research findings to be inadequate for making recommendations “for or against the use of low carbohydrate diets to induce weight loss, especially for durations longer than 6 months” (Nordmann et al., 2006, p. 292). After the first year, the differences in weight loss between low carbohydrate and low fat diets were insignificant, and not suited for practical application (Nordmann et al., 2006). The occurrence of beneficial changes in low density lipoprotein cholesterol (LDL-C) levels counters against drawing the conclusion that low carbohydrate diets can be recommended to promote weight loss (Nordmann et al., 2006). The authors assert that “no trials of low carbohydrate diets have been performed towards clinical end points such as myocardial infarction or death” (Nordmann et al., 2006, p. 292). Hence, there is continued doubt regarding the beneficial effects of these diets on HDL-C and triglyceride levels (Nordmann et al., 2006). Low carbohydrate diets cannot be used for preventing cardiovascular disease, because there is little evidence on lowering cardiovascular morbidity and mortality by low carbohydrate diets (Nordmann et al., 2006). Samaha, Iqbal, Seshadri et al. (2003) determined the effects of a carbohydrate restricted diet on weight loss and atherosclerosis, using two obese groups of people, either on a carbohydrate restricted diet or a calorie and fat restricted diet (Samaha et al., 2003). The results indicate that severely obese subjects with a high rate of diabetes or the metabolic syndrome “lost more weight during six months on a carbohydrate-restricted diet than on a calorie and fat restricted diet, with a relative improvement in insulin sensitivity and triglyceride levels” (Samaha et al., 2003, p. 2074), “even after the amount of weight lost was adjusted”. Because of the small time-frame of the study, and the small variations in weight loss in general as well as between the two groups (Samaha et al., 2003), low carbohydrate diets can be recommended for reducing cardiovascular problems only with evidence from longer term future studies (Samaha et al., 2003). According to Yancy et al. (2004), although there is a lack of scientific evidence to support the use of low carbohydrate diets, this strategy continues to be widely used. Yancy et al. (2004) undertook research using a randomized, controlled trial, to compare the consequences of “a low carbohydrate, ketogenic diet program with those of a low fat, low cholesterol, decreased calorie diet” (Yancy et al., 2004, p. 769), using “120 overweight, hyperlipidimic volunteers from the community”. One section of the group was provided with a low carbohydrate diet of initially less than 20 grams of carbohydrates daily, together with nutritional supplementation, exercise recommendation, and group meetings (Yancy et al., 2004). The other section was given a low fat diet, with less than 30% energy from fat, along with exercise recommendation and group meetings (Yancy et al., 2004). The participants were measured for “body weight, body composition, fasting serum lipid levels, and tolerability” (Yancy et al., 2004, p. 769). The evidence from this 24 weeks’ study indicates that participants were retained to a greater extent, and greater weight loss occurred from using the low carbohydrate diet program, as compared to the low fat program (Yancy et al., 2004). During the process of weight loss, the low carbohydrate diet caused greater lowering in serum triglyceride levels and increase in high density lipoprotein cholesterol level than the low fat diet (Yancy et al., 2004). Thus, “healthy hyperlipidic individuals following a low carbohydrate diet lost more body weight and body fat, as compared to those who undertook a low fat diet” (Yancy et al., 2004, p. 769). Although serum lipid profiles improved in both groups, supervision was carried out because of the risk of adverse changes taking place for a small percentage of the participants. Hence, the safety of the low carbohydrate dietary approach needs further supportive evidence (Yancy et al., 2004). A meta-analysis of randomized controlled trials was carried out on the effects on metabolic risk factors, of “low carbohydrate diets containing 45% of energy from carbohydrates, versus low fat diets with approximately 30% of energy from fat” (Hu, Mills, Yao, et al., 2012, S44). The research studies included 23 randomized controlled trials from several countries, conducted between January 1966 to June 2011, encompassing a total of 2,788 participants (Hu et al., 2012). The evidence reveals that “both low-carbohydrate and low-fat diets lowered weight and improved metabolic risk factors” (Hu et al., 2012, S44). At the same time, however, on a comparative basis, participants on low carbohydrate diets underwent a “slight but statistically significant lower reduction in total cholesterol and low density lipoprotein cholesterol, but a greater increase in both high density lipoprotein cholesterol and in triglycerides” (Hu et al., 2012, S44). Contrastingly, according to Hu et al. (2012, S44), “reductions in body weight, waist circumference and other metabolic risk factors were not significantly different between the 2 diets”. These findings establish the equal effectiveness of low fat diets and low carbohydrate diets, in leading to weight loss and benefits to metabolic risk factors (Hu et al., 2012). At the same time, improved cardiac health is achieved from “the use of low carbohydrate diets by obese persons with abnormal metabolic risk factors” (Hue et al., 2012, S44). A systematic review of research studies using randomized controlled trials of low carbohydrate versus low fat/low calorie diets in treating obesity and related diseases, was conducted by Hession, Rolland, Kulkarni et al. (2008). The evidence reveals that “low carbohydrate/ high protein diets are more effective at 6 months and are as effective, if not more, as low-fat diets in reducing weight and cardiovascular disease risk up to 1 year” (Hession et al., 2008, p. 36). Hence, longer term studies would help to evaluate the cardiovascular improvements resulting from weight loss incurred through following these diets (Hession et al., 2008). Conclusion This paper has compared low carbohydrate diets with low fat diets, and investigated their results in relation to weight loss and improvement of metabolic disorders in the body. The evidence overall indicates that both types of diets are equally beneficial in achieving weight loss and increased health benefits (Nordmann et al., 2006; Hue et al., 2012). However, Hue et al. (2012) support the use of low carbohydrate diets for improved heart health. Similarly, studies by Yancy et al. (2004) reveal that there is a greater support for low carbohydrate diets as more beneficial for treating obesity and related diseases such as diabetes due to insulin resistance, fatty liver disease, hypertension, and cardiovascular conditions. In the same way, Forsythe et al. (2008), NHR (2011) and NHR (2010) support the use of low carbohydrate diets for reducing liver fat. Instead of the use of drugs to combat obesity and consequent diseases, USA Today (2010) recommends shifting to a low carbohydrate diet for improved results. On the other hand, Nordmann et al. (2006, p. 285) observe that “low carbohydrate diets derive a large proportion of energy intake from protein and fat” due to which “blood lipid levels and cardiovascular risk” may be adversely affected. The authors state that there is inadequate evidence from research studies to support or prevent the use of low carbohydrate diets. Hence, Samaha et al. (2003) support the requirement for longer term studies to confirm the comparatively greater benefits of low carbohydrate diets on cardiovascular health. Therefore, it is concluded that weight loss irrespective of the method, is the most effective way to reduce liver fat and its impacts, as well as other potentially fatal metabolic disorders of vital organs and systems. Thus, long term and continued adherence to a low carbohydrate or a low fat diet, together with implementing an exercise regimen are the most effective measures for achieving weight loss and health benefits. References Forsythe, C. E., Phinney, S. D., Fernandez, M. L., Quann, E. E., Wood, R. J., Bibus, D. M., Kraemer, W. J., et al. (2008). Comparison of low fat and low carbohydrate diets on circulating fatty acid composition and markers of inflammation. Lipids, 43(1), 65-77. Hession, M., Rolland, C., Kulkarni, U., Wise, A., & Broom, J. (2008). Systematic review of randomized controlled trials of low-carbohydrate vs. low-fat/low-calorie diets in the management of obesity and its comorbidities. Obesity Reviews, 10(1), 36-50. Hu, T., Mills, K.T., Yao, L., Demanelis, K., Eloustaz, M., Yancy, W. S. Jr., Kelly, T.N., He, J., & Bazzanalo, L.A. (2012). Effects of low-carbohydrate diets versus low-fat diets on metabolic risk factors: A meta-analysis of randomized controlled clinical trials. American Journal of Epidemiology, 176(Suppl 7), S44-54. NHR (Nutrition Health Review). (2010). Low-carbohydrate diet burns more excess liver fat than low-calorie diets. Nutrition Health Review, 101, 16. NHR (Nutrition Health Review). (2011). Limiting carbohydrates, not calories may reduce liver fat faster. Nutrition Health Review, 105, 4. Nordmann, A. J., Nordmann, A., Briel, M., Keller, U., Yancy, W .S., Brehm, B., & Bucher, H.C. (2006). Effects of low-carbohydrate vs low-fat diets on weight loss and cardiovascular risk factors: A meta-analysis of randomized controlled trials. Archives of Internal Medicine, 166(3), 285-293. Samaha, F. F., Iqbal, N., Seshadri, P., Chicano, K.L., Daily, D.A., McGrory, J., Williams, T., Williams, M., Gracely, E. J., & Stern, L. (2003). A low-carbohydrate as compared with a low-fat diet in severe obesity. New England Journal of Medicine, 348(21), 2074-2081. USA Today. (2010 January). Low-carb diets burn more fat. USA Today, 138, 8. Yancy, W. S., Olsen, M. K., Guyton, J. R., Bakst, R. P., & Westman, E. C. (2004). A low- carbohydrate, ketogenic diet versus a low-fat diet to treat obesity and hyperlipidemia: A randomized, controllled trial. Annals of Internal Medicine, 140(10), 769-779. Read More