Article

A Statement of the American Heart Association Nutrition Committee on Dietary Protein and Weight Reduction: A Rigorous Rebuttal

Authors:
  • Dominus Nutrition Oy
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Abstract

Results of several recent studies show that high-protein, low-carbohydrate weight loss diets indeed have their benefits. However, there are always some concerns about high-protein diets. According to the American Heart Association (AHA) Nutrition Committee, highprotein diets may possess significant health risks. The purpose of this review is to evaluate the scientific validity of AHA Nutrition CommitteeA s statement on dietary protein and weight reduction (St. Jeor ST et al. Circulation 2001;104:1869-1874). Simply stated, there is little if any scientific evidence supporting above mentioned statement. Certainly, such public warnings should be based on a thorough analysis of the scientific literature, not unsubstantiated fears and misrepresentations. For individuals with normal renal function, the risks are minimal and must be balanced against the real and established risk of continued obesity.

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... On the whole, undoubtedly, this approach that was considered with caution fifteen years ago [14][15] appears to be a powerful tool against obesity, even more if it is accompanied by metabolic complications. ...
... When we started this series of studies in the late nineties protein addition to diet was actually considered with caution [14,15]. However, the idea to preequilibrated protein intake around 1.2 g.kg -1.day -1 gained little by little more audience and our finding of the fair efficiency of this approach is in accordance with some recent literature. ...
... This is certainly problematic for renal-compromised individuals but no evidence indicates that high protein diets (e.g., two to three times the RDA) diminish renal function in healthy people. [45][46][47][48] Some concern also exists that higher-protein diets may be detrimental to bone because calcium excretion is increased when consuming a high, relative to a low, protein diet. This effect is thought to originate from bone in an attempt to buffer the metabolic acidity of protein catabolism. ...
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Military recommendations for dietary protein are based on the recommended dietary allowance (RDA) of 0.8 g of protein per kilogram of body mass (BM) established by the Food and Nutrition Board, Institute of Medicine (IOM) of the National Academies. The RDA is likely adequate for most military personnel, particularly when activity levels are low and energy intake is sufficient to maintain a healthy body weight. However, military recommendations account for periods of increased metabolic demand during training and real-world operations, especially those that produce an energy deficit. Under those conditions, protein requirements are higher (1.5-2.0 g/kg BM) in an attempt to attenuate the unavoidable loss of muscle mass that occurs during prolonged or repeated exposure to energy deficits. Whole foods are recommended as the primary method to consume more protein, although there are likely operational scenarios where whole foods are not available and consuming supplemental protein at effective, not excessive, doses (20-25 g or 0.25-0.3 g/kg BM per meal) is recommended. Despite these evidence-based, condition-specific recommendations, the necessity of protein supplements and the requirements and rationale for consuming higher-protein diets are often misunderstood, resulting in an overconsumption of dietary protein and unsubstantiated health-related concerns. This review will provide the basis of the US military dietary protein requirements and highlight common misconceptions associated with the amount and safety of protein in military diets. 2015.
... There is no evidence, however, that renal function in healthy individuals is diminished by consuming higher protein diets (Martin and others 2005). Glomerular filtration rate generally increases when consuming higher protein diets (Schwingshackl and Hoffmann 2014), but renal function is not compromised, particularly in healthy, physically active individuals consuming 2 to 3 times the RDA for protein (Poortmans and Dellalieux 2000;Manninen 2004). The IOM (National Academy of Sciences 2005), WHO (World Health Organization 2011), and the Australian and New Zealand (2014) reports on dietary protein requirements are in agreement and state that there is no link between higher protein intake and renal dysfunction in healthy adults. ...
Article
The Inst. of Medicine and World Health Organization have determined that 0.8 to 0.83 g protein·kg(-1) ·d(-1) is the quantity of protein required to establish nitrogen balance in nearly all healthy individuals. However, consuming higher protein diets may be metabolically advantageous, particularly for overweight and obese adults attempting weight loss, and for physically active individuals such as athletes and military personnel. Studies have demonstrated that higher protein diets may spare lean body mass during weight loss, promote weight management, enhance glycemic regulation, and increase intestinal calcium absorption, which may result in long-term improvements in bone health. The extent to which higher protein diets are beneficial is largely attributed to the digestive and absorptive properties, and also to the essential amino acid (EAA) content of the protein. Proteins that are rapidly digested and absorbed likely contribute to the metabolic advantages conferred by consuming higher protein diets. The EAA profiles, as well as the digestive and absorptive properties of dairy proteins, such as whey protein and casein, are particularly advantageous because they facilitate a rapid, robust, and sustained delivery of EAAs to the periphery. This article reviews the scientific literature assessing metabolic advantages associated with higher protein diets on weight management, glycemic regulation, and bone, with emphasis given to studies evaluating the potential benefits associated with dairy. © 2015 Institute of Food Technologists®
... 2004) ja proteiinien aiheuttama kylläisyyden tunne on suuri (Hall ym. 2003 (Hoffman & Falvo 2004;Manninen 2004b). Uusien proteiinien muodostus ja varastointi on rajallista, joten ylimääräisistä ravinnosta saaduista proteiinien aminohapoista poistetaan aminoryhmät, jotka käytetään urean muodostukseen ja vastaavasti hiilirungot hapetetaan energiaksi tai varastoidaan glykogeeniksi tai rasvaksi (Maughan & Burke 2002, 26). ...
... In order to achieve optimal effects of diet on growth and body composition, optimal proportions among macronutrients has been extensively discussed, without a definite consensus [6][7][8][9]. Studies, mainly performed with adults, have demonstrated advantageous consequences of high-protein diets, such as reduction of body fat [8,10], decrease in lipogenesis [11] and boosting of energy expenditure, protein balance and satiety [12]. On the other hand, it is not clear whether a high protein intake might further enhance the lean body mass [8,13]. ...
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It was recently shown that glucose challenge leads to increased generation of reactive oxygen species (ROS) by polymorphonuclear leukocytes (PMNs) and mononuclear cells (MNCs). To further elucidate the relation between nutrition and ROS generation, we investigated the effect of lipid and protein challenges on ROS generation by leukocytes. After having fasted overnight, one group of healthy subjects consumed a carbohydrate- and protein-free cream preparation (1257 kJ) and another group of healthy subjects consumed an equienergetic pure preparation of casein. Sequential blood samples were obtained after the intake of cream and casein. ROS were measured by chemiluminescence after stimulation by N-formyl-methionyl-leucinyl-phenylalanine. Lipid peroxidation was measured as thiobarbituric acid-reactive substances (TBARS) and alpha-tocopherol was measured by HPLC. ROS generation by MNCs and PMNs increased significantly 1, 2, and 3 h after cream intake and 1 h after protein intake. Cholesterol concentrations did not change significantly, whereas triacylglycerol concentrations increased significantly 2 h after cream intake. Total TBARS concentrations increased 1 h after cream intake and remained elevated 3 h after intake, but the increase was not significant when corrected for changes in triacylglycerol. After casein intake, total cholesterol, triacylglycerol, and TBARS concentrations did not change significantly. alpha-Tocopherol concentrations did not change significantly after either cream or casein intake. Both fat and protein intakes stimulate ROS generation. The increase in ROS generation lasted 3 h after cream intake and 1 h after protein intake. Cream intake also caused a significant and prolonged increase in lipid peroxidation. These data are important because increased ROS generation and lipid peroxidation are key events in atherogenesis.
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The few studies that have examined body composition after a carbohydrate-restricted diet have reported enhanced fat loss and preservation of lean body mass in obese individuals. The role of hormones in mediating this response is unclear. We examined the effects of a 6-week carbohydrate-restricted diet on total and regional body composition and the relationships with fasting hormone concentrations. Twelve healthy normal-weight men switched from their habitual diet (48% carbohydrate) to a carbohydrate-restricted diet (8% carbohydrate) for 6 weeks and 8 men served as controls, consuming their normal diet. Subjects were encouraged to consume adequate dietary energy to maintain body mass during the intervention. Total and regional body composition and fasting blood samples were assessed at weeks 0, 3, and 6 of the experimental period. Fat mass was significantly (P <or=.05) decreased (-3.4 kg) and lean body mass significantly increased (+1.1 kg) at week 6. There was a significant decrease in serum insulin (-34%), and an increase in total thyroxine (T(4)) (+11%) and the free T(4) index (+13%). Approximately 70% of the variability in fat loss on the carbohydrate-restricted diet was accounted for by the decrease in serum insulin concentrations. There were no significant changes in glucagon, total or free testosterone, sex hormone binding globulin (SHBG), insulin-like growth factor-I (IGF-I), cortisol, or triiodothyronine (T(3)) uptake, nor were there significant changes in body composition or hormones in the control group. Thus, we conclude that a carbohydrate-restricted diet resulted in a significant reduction in fat mass and a concomitant increase in lean body mass in normal-weight men, which may be partially mediated by the reduction in circulating insulin concentrations.
Relationship of dietary variables to blood pressure (BP) findings of the Multiple Risk Factors Intervention Study (MRFIT)
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Stamler JS, Caggiuala A, Grandist GA. Relationship of dietary variables to blood pressure (BP) findings of the Multiple Risk Factors Intervention Study (MRFIT).
Nutrition support and management of renal disorders Nutritional Aspects and Clinical Management of Chronic Disorders and Diseases
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Ikizler TA. Nutrition support and management of renal disorders. In: Bronner, F. ed. Nutritional Aspects and Clinical Management of Chronic Disorders and Diseases. Boca Raton, FL: CRC Press, 2003, pp. 156-175.
Dietary protein and weight reduction: A statement for health care professionals from the Nutrition Committee of the Council on Nutrition
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Effects of protein intake on renal function and on the development of renal disease. In: The Role of Protein and Amino Acids in Sustaining and Enhancing Performance. Committee on Military Nutrition Re-search, Institute of Medicine
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Walser M. Effects of protein intake on renal function and on the development of renal disease. In: The Role of Protein and Amino Acids in Sustaining and Enhancing Performance. Committee on Military Nutrition Re-search, Institute of Medicine. Washington, DC: Na-tional Academies Press, 1999:137–154.
High-protein intake-Is it safe?
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Street C. High-protein intake-Is it safe? In: Antonio J, Stout JR, eds. Sports Supplements. Philadelphia: Lippincott Williams & Wilkins, 2001, pp. 311-312.
Nutrition and alcoholism Nutritional Aspects and Clinical Management of Chronic Disorders and Diseases
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Navder KP, Lieber CS. Nutrition and alcoholism. In: Bronner, F. ed. Nutritional Aspects and Clinical Management of Chronic Disorders and Diseases. Boca Raton, FL: CRC Press, 2003, pp. 307-320.
Effects of protein intake on renal function and on the development of renal disease In: The Role of Protein and Amino Acids in Sustaining and Enhancing Performance
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Walser M. Effects of protein intake on renal function and on the development of renal disease. In: The Role of Protein and Amino Acids in Sustaining and Enhancing Performance. Committee on Military Nutrition Research, Institute of Medicine.
Nutritional support in chronic disease of the gastrointestinal tract and the liver Nutritional Aspects and Clinical Management of Chronic Disorders and Diseases
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Navder KP, Lieber CS. Nutritional support in chronic disease of the gastrointestinal tract and the liver. In: Bronner, F. ed. Nutritional Aspects and Clinical Management of Chronic Disorders and Diseases. Boca Raton, FL: CRC Press, 2003, pp. 45-68.