Calorie for Calorie, Dietary Fat Restriction Results in More Body Fat Loss than Carbohydrate Restriction in People with Obesity

“The net macronutrient oxidation rates determined by the indirect calorimetry equations above include the influence of gluconeogenesis (GNG) from amino acids and de novo lipogenesis (DNL) from carbohydrates (Frayn, 1983).”

“…that previously observed differences in weight loss and body fat change during outpatient diet interventions (Foster et al., 2010; Gardner et al., 2007; Shai et al., 2008) were primarily due to differences in overall calorie intake rather than any metabolic advantage of a low-carbohydrate diet.”

“Energy expenditure (EE) and net macronutrient oxidation rates were calculated using the coefficients derived by Livesey and Elia (Livesey and Elia, 1988)”

“Since diet adherence is likely the most important determinant of body fat loss, we suspect that previously observed differences in weight loss and body fat change during outpatient diet interventions (Foster et al., 2010; Gardner et al., 2007; Shai et al., 2008) were primarily due to differences in overall calorie int…”

“…previous claims about a metabolic advantage of carbohydrate restriction for enhancing body fat loss (Ludwig and Friedman, 2014; Taubes, 2007, 2011; Westman et al., 2007), our data and model simulations support the opposite conclusion 430 Cell Metabolism 22, 427–436, September 1, 2015 ª2015…”

“As an alternative, controlled feeding studies can provide more useful physiological information, but diet adherence is often poor in outpatient studies even when participants are provided with all of their food (Das et al., 2007).”

“A mechanistic mathematical model of human macronutrient metabolism (Hall, 2010) was used to design the study and predict the metabolic response to each diet before the studywas conducted (Hall, 2012).”

“…investigate differences in weight loss (Anderson, 1944; Bell et al., 1969; Bogardus et al., 1981; Bortz et al., 1967, 1968; Fletcher et al., 1961; Golay et al., 1996; Kekwick and Pawan, 1956; Kinsell et al., 1964; Lewis et al., 1977; Miyashita et al., 2004; Olesen and Quaade, 1960; Pilkington et…”

“C sensitivity to detect small differences in body fat change (Hind et al., 2011; Lohmanet al., 2009;Müller et al., 2012).”

“Five of the previous inpatient feeding studies attempted to measure differences in body fat resulting from varying carbohydrate and fat, but no significant differences were found (Bogardus et al., 1981; Golay et al., 1996; Miyashita et al., 2004; Rumpler et al., 1991; Yang and Van Itallie, 1976).”

“…weight loss with reduced carbohydrate diets (Anderson, 1944; Bell et al., 1969; Bogardus et al., 1981; Bortz et al., 1967, 1968; Kekwick and Pawan, 1956; Lewis et al., 1977; Olesen and Quaade, 1960; Pilkington et al., 1960; Rabast et al., 1979, 1981; Werner, 1955; Yang and Van Itallie, 1976).”

“…1967, 1968; Fletcher et al., 1961; Golay et al., 1996; Kekwick and Pawan, 1956; Kinsell et al., 1964; Lewis et al., 1977; Miyashita et al., 2004; Olesen and Quaade, 1960; Pilkington et al., 1960; Rabast et al., 1979, 1981; Rumpler et al., 1991; Vazquez and Adibi, 1992; Vazquez et al., 1995;…”

“…al., 1981; Bortz et al., 1967, 1968; Fletcher et al., 1961; Golay et al., 1996; Kekwick and Pawan, 1956; Kinsell et al., 1964; Lewis et al., 1977; Miyashita et al., 2004; Olesen and Quaade, 1960; Pilkington et al., 1960; Rabast et al., 1979, 1981; Rumpler et al., 1991; Vazquez and Adibi, 1992;…”

“…2008), but such outpatient studies are difficult to interpret mechanistically because it is not currently possible to accurately measure adherence to the recommended diets since the instruments for assessing food intake rely on selfreport and have been demonstrated to be biased (Winkler, 2005).”

“The model also implicated small persistent changes in protein balance resulting from the fact that dietary carbohydrates preserve nitrogen balance to a greater degree than fat (Bell et al., 1969; Vazquez and Adibi, 1992; Vazquez et al., 1995).”

“…diets with fixed protein and varying in carbohydrate and fat to investigate differences in weight loss (Anderson, 1944; Bell et al., 1969; Bogardus et al., 1981; Bortz et al., 1967, 1968; Fletcher et al., 1961; Golay et al., 1996; Kekwick and Pawan, 1956; Kinsell et al., 1964; Lewis et…”

“However, several studies did not detect significant differences in weight loss (Fletcher et al., 1961; Golay et al., 1996; Kinsell et al., 1964; Miyashita et al., 2004; Rumpler et al., 1991; Vazquez and Adibi, 1992; Vazquez et al., 1995).”

“…weight loss with reduced carbohydrate diets (Anderson, 1944; Bell et al., 1969; Bogardus et al., 1981; Bortz et al., 1967, 1968; Kekwick and Pawan, 1956; Lewis et al., 1977; Olesen and Quaade, 1960; Pilkington et al., 1960; Rabast et al., 1979, 1981; Werner, 1955; Yang and Van Itallie, 1976).”

“Most of these studies used body composition assessmentmethodologies to measure body fat changes (Bogardus et al., 1981; Golay et al., 1996; Miyashita et al., 2004; Rumpler et al., 1991).”

“The model also implicated small persistent changes in protein balance resulting from the fact that dietary carbohydrates preserve nitrogen balance to a greater degree than fat (Bell et al., 1969; Vazquez and Adibi, 1992; Vazquez et al., 1995).”

“…weight loss with reduced carbohydrate diets (Anderson, 1944; Bell et al., 1969; Bogardus et al., 1981; Bortz et al., 1967, 1968; Kekwick and Pawan, 1956; Lewis et al., 1977; Olesen and Quaade, 1960; Pilkington et al., 1960; Rabast et al., 1979, 1981; Werner, 1955; Yang and Van Itallie, 1976).”

“Since body composition assessment methods are insufficiently sensitive to measure short-term body fat change during active energy imbalance (Lohman et al., 2000; Müller et al., 2012; Pourhassan et al., 2013; Valentine et al., 2008), body fat change was determined using cumulative net fat balance as determined by indir…”

“The model also implicated small persistent changes in protein balance resulting from the fact that dietary carbohydrates preserve nitrogen balance to a greater degree than fat (Bell et al., 1969; Vazquez and Adibi, 1992; Vazquez et al., 1995).”

“…weight loss with reduced carbohydrate diets (Anderson, 1944; Bell et al., 1969; Bogardus et al., 1981; Bortz et al., 1967, 1968; Kekwick and Pawan, 1956; Lewis et al., 1977; Olesen and Quaade, 1960; Pilkington et al., 1960; Rabast et al., 1979, 1981; Werner, 1955; Yang and Van Itallie, 1976).”

“But even high-precision methods, such as DXA, may lack the Cell Me sensitivity to detect small differences in body fat change (Hind et al., 2011; Lohmanet al., 2009;Müller et al., 2012).”

“…difference from baseline at p = 0.001; ** indicates a significant difference between RC and RF at p < 0.0001. water imbalances (Anderson, 1944; Bell et al., 1969; Bortz et al., 1967, 1968; Lewis et al., 1977;Olesen andQuaade, 1960;Pilkington et al., 1960; Werner, 1955; Yang and Van Itallie, 1976).”

“Since body composition assessment methods are insufficiently sensitive to measure short-term body fat change during active energy imbalance (Lohman et al., 2000; Müller et al., 2012; Pourhassan et al., 2013; Valentine et al., 2008), body fat change was determined using cumulative net fat balance as determined by indir…”

“…difference from baseline at p = 0.001; ** indicates a significant difference between RC and RF at p < 0.0001. water imbalances (Anderson, 1944; Bell et al., 1969; Bortz et al., 1967, 1968; Lewis et al., 1977;Olesen andQuaade, 1960;Pilkington et al., 1960; Werner, 1955; Yang and Van Itallie, 1976).”

“A mechanistic mathematical model of human macronutrient metabolism (Hall, 2010) was used to design the study and predict the metabolic response to each diet before the studywas conducted (Hall, 2012).”

“Several randomized controlled trials have demonstrated greater short-term weight loss when advising obese patients to restrict dietary carbohydrates (Foster et al., 2010; Gardner et al., 2007; Shai et al., 2008), but such outpatient studies are difficult to interpret mechanistically because it is…”

“…a significant difference from baseline at p = 0.001; ** indicates a significant difference between RC and RF at p < 0.0001. water imbalances (Anderson, 1944; Bell et al., 1969; Bortz et al., 1967, 1968; Lewis et al., 1977;Olesen andQuaade, 1960;Pilkington et al., 1960; Werner, 1955; Yang…”

“which assumes that protein oxidation contributes 15% to the energy expenditure (6).”

“The energy expended in physical activities is determined by their duration and intensity in proportion to overall body weight.(13) Thus, despite typically being less physically active, people with obesity often have similar daily energy costs for physical activity as those without obesity (Figure 1A)(14) and physical…”

“Unfortunately, work of this nature is expensive, labor intensive and generally of short duration with small sample sizes [91].”