Previously, we discussed the importance of moving an individual’s paradigm away from calorie quantity and toward calorie quality in the battle against obesity. Re-educating individuals about the metabolic differences between protein, fat, and carbohydrates, in regards to obesity will give them confidence to abandon the old theory of calorie-counting and embrace current literature, which gives preference to the type of calorie consumed.
We reviewed the benefits of adequate protein consumption during weight loss to include preservation of lean muscle mass and a healthy metabolic rate to prevent a shift toward energy conservation. We also reviewed the benefits of healthy fat consumption, which ensures satiety, a healthy rate of fat oxidation, and a favorable shift toward gluconeogenesis to encourage energy utilization and weight loss.
Now we will review the role of carbohydrates in weight management. Unarguably, in the weight loss arena, this has been a buzz topic of the decade, leading to a trend toward low-carb, Paleo-type dietary patterns. Not only is the anecdotal evidence strong among practitioners using these dietary patterns for health support, but literature is verifying the success that many practitioners are witnessing.
Ever since the USDA published a food pyramid with an emphasis on grains and breads, the carbohydrate intake of America has been steadily growing and is the basis of the standard American diet. Ironically (or should we say understandably), the obesity epidemic has developed and persisted, in the wake of these guidelines. Even a recent statement by the British Journal of Sports Medicine alluded to the fact that “research indicates that cutting down on dietary carbohydrate is the single most effective approach for reducing all of the features of the metabolic syndrome and should be the primary strategy for treating diabetes, with benefits occurring even in the absence of weight loss.” For the obese individual, who may not understand how high carbohydrate foods could promote weight gain, it is important to educate them about the low energy cost of carbohydrate metabolism (digestion, absorption, and storage), which often leads to a faster energy deficit and, therefore, an increased appetite and metabolic shifts that favor energy storage. The cycle is vicious and counterproductive for weight loss or weight management.
When reviewing the literature, we see that the metabolic success of low carb diets in long-term weight management is partially dependent on a corresponding increase in protein consumption. This is the caveat, which has created controversy within studies on isocaloric versus low carb diets for weight loss. A meta-regression study that sought to observe the effects of various protein and carbohydrate intakes on body mass and composition during energy restriction, concluded, “Low-carbohydrate, high-protein diets favorably affect body mass and composition independent of energy intake, which in part supports the proposed metabolic advantage of these diets.” Energy restriction alone can result in temporary weight loss, but long-term weight management is hinged on the preservation of fat free mass, which occurs when carbohydrates are restricted and a natural increase in protein and fat consumption is allowed.
Popular trends towards a Paleolithic diet also support a movement away from carbohydrates, originating from grain-sources and toward a high protein, low carb dietary pattern. In a study that compared weight loss and lipid plasma lipid ratios after participants consumed the traditionally recommended heart healthy diet and a Paleolithic diet, it was found that, “Paleolithic nutrition significantly lowered (P < .001) mean total cholesterol, LDL, and TG and increased (P < .001) HDL, independent of changes in body weight, relative to both baseline and the traditional heart-healthy diet.” Accordingly, a Paleolithic diet improves fat oxidation, which not only results in desired fat loss, but also healthy cardiovascular parameters, compared to current recommendations for a grain-based diet.
Patients attempting to lose weight according to the traditional recommendations for a low fat diet are more likely to consume a higher level of carbs, leading to a frustrating, yo-yo type weight loss journey. The enduring “old school of thought” that promotes a low-calorie, low-fat diet for weight loss can only be changed through proper education in macronutrient distribution.