Effects of a Low-Carbohydrate Diet on Cardiometabolic Risk Factors During Weight-Loss Maintenance: A Randomized Controlled Feeding Trial

Abstract Objectives To compare effects of diets varying in carbohydrate (carb) and fat on plasma lipids and lipoprotein subfractions. Methods Participants (N = 164, 70% female, 18–65 y, BMI ≥ 25 kg/m2) achieved 10–14% weight loss on a run-in diet and then were randomized to 3 test diets for 20 weeks of weight-loss maintenance. Percentages of total energy from carb-fat-protein for high-, moderate-, and low-carb diets were 60-20-20 (HI), 40-40-20 (MOD), and 20–60-20 (LO). Relative amounts of added sugar (15% total carb) and saturated fat (35% total fat) were fixed across diets. Plasma was collected at START (post-weight loss) and END of trial. The primary outcome for this ancillary study was lipoprotein insulin resistance (LPIR) – a 6-component weighted score of triglyceride-rich, high-density, and low-density lipoprotein particle (TRL-P, HDL-P, LDL-P) sizes and subfraction concentrations (large/very large TRL-P, large HDL-P, small LDL-P) (NMR spectroscopy, LabCorp). Other outcomes included large LDL-P concentration, triglycerides (TG), and cholesterol (HDL-C, LDL-C). Means (±SE) and END–START changes (mean [95% CI]) were constructed and compared from repeated measures ANOVA. Results Retention was 90% and 147 participants provided evaluable data, with no difference in body weight by diet after randomization. LPIR was 32.6 ± 1.5 at START. Change in LPIR differed by diet (P = 0.009): LO (−5.3 [−9.2, −1.5]), MOD (−0.02 [−4.1, 4.1]), HI (3.6 [−0.6, 7.7]). Diet effects favoring LO compared to HI were observed for large/very large TRL-P (P = 0.005), large HDL-P (P = 0.045), TG (P = 0.006), and HDL-C (P = 0.04). There were no mean differences between diets for particle sizes, LDL-P subfraction concentrations, and LDL-C (START: 79.3 ± 1.8 mg/dL; END–START: HI, 8.2 [4.2, 12.2]; MOD, 11.7 [7.8, 15.7]; LO, 10.0 [6.3, 13.7]). Conclusions With 3-fold higher saturated fat content (21% vs 7% total energy), a low- vs high-carb diet improved LPIR, a biomarker of diabetes risk, and several other components of the metabolic syndrome, with no adverse effects on LDL-P or LDL-C. These results from a large feeding study suggest that carb restriction may help prevent cardiometabolic disease independent of body weight. Funding Sources Nutrition Science Initiative (gifts from Arnold Ventures and Robert Lloyd Corkin Charitable Foundation), New Balance Foundation, Many Voices Foundation, Blue Cross Blue Shield.

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Energy Requirement Is Higher During Weight-Loss Maintenance in Adults Consuming a Low- Compared with High-Carbohydrate Diet

Journal of Nutrition ◽

10.1093/jn/nxaa150 ◽

2020 ◽

Vol 150 (8) ◽

pp. 2009-2015 ◽

Cited By ~ 3

Author(s):

Cara B Ebbeling ◽

Lisa Bielak ◽

Paul R Lakin ◽

Gloria L Klein ◽

Julia M W Wong ◽

...

Keyword(s):

Weight Loss ◽

Energy Expenditure ◽

Total Energy ◽

Energy Requirement ◽

Weight Loss Maintenance ◽

High Carbohydrate Diet ◽

Carbohydrate Diet ◽

Low Carbohydrate Diet ◽

High Carbohydrate ◽

Low Carbohydrate

ABSTRACT Background Longer-term feeding studies suggest that a low-carbohydrate diet increases energy expenditure, consistent with the carbohydrate-insulin model of obesity. However, the validity of methodology utilized in these studies, involving doubly labeled water (DLW), has been questioned. Objective The aim of this study was to determine whether dietary energy requirement for weight-loss maintenance is higher on a low- compared with high-carbohydrate diet. Methods The study reports secondary outcomes from a feeding study in which the primary outcome was total energy expenditure (TEE). After attaining a mean Run-in weight loss of 10.5%, 164 adults (BMI ≥25 kg/m2; 70.1% women) were randomly assigned to Low-Carbohydrate (percentage of total energy from carbohydrate, fat, protein: 20/60/20), Moderate-Carbohydrate (40/40/20), or High-Carbohydrate (60/20/20) Test diets for 20 wk. Calorie content was adjusted to maintain individual body weight within ± 2 kg of the postweight-loss value. In analyses by intention-to-treat (ITT, completers, n = 148) and per protocol (PP, completers also achieving weight-loss maintenance, n = 110), we compared the estimated energy requirement (EER) from 10 to 20 wk of the Test diets using ANCOVA. Results Mean EER was higher in the Low- versus High-Carbohydrate group in models of varying covariate structure involving ITT [ranging from 181 (95% CI: 8–353) to 246 (64–427) kcal/d; P ≤0.04] and PP [ranging from 245 (43–446) to 323 (122–525) kcal/d; P ≤0.02]. This difference remained significant in sensitivity analyses accounting for change in adiposity and possible nonadherence. Conclusions Energy requirement was higher on a low- versus high-carbohydrate diet during weight-loss maintenance in adults, commensurate with TEE. These data are consistent with the carbohydrate-insulin model and lend qualified support for the validity of the DLW method with diets varying in macronutrient composition. This trial was registered at clinicaltrials.gov as NCT02068885.

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Effect of Mixed Nuts on Body Weight and Composition, and Gut Microbiome (P08-054-19)

Current Developments in Nutrition ◽

10.1093/cdn/nzz044.p08-054-19 ◽

2019 ◽

Vol 3 (Supplement_1) ◽

Author(s):

Shih Lung Woo ◽

Dina Ben-Nissan ◽

Zahra Ezzat-Zadeh ◽

Jieping Yang ◽

Lijun Zhang ◽

...

Keyword(s):

Weight Loss ◽

Body Composition ◽

Body Weight ◽

Gut Microbiome ◽

Plasma Lipids ◽

Plasma Lipid ◽

Healthy Weight ◽

Weight Changes ◽

Fecal Microbiome ◽

Tree Nuts

Abstract Objectives This study was designed to assess the effects of mixed nut consumption on body weight and composition, and gut microbiome in obese individuals. Primary outcome was change in body weight and composition. Secondary outcomes include gut microbiome composition, inflammatory markers, and plasma lipids. Methods The reported results are from an interim analysis (n = 50) of a randomized, placebo controlled, parallel study. Total enrollment target is 154 overweight/obese subjects (BMI 27–35 kg/m2). Participants were randomly assigned to consume either 1.5oz mixed tree nuts or pretzels with equal calorie content daily for 24 weeks. The study included a 12-week weight loss phase (500 kcal per day less than total daily energy expenditure), followed by a 12-week weight maintenance phase. Body composition, fasting blood, and stool samples were collected at baseline, week 12 and 24. Body composition, and vitals were analyzed, whereas plasma lipid profile, fecal microbiome, and microbiome metabolites analysis is still pending. Results At week 12, subjects from both the pretzel (n = 15, 10 dropouts; P = 0.009) and nut group (n = 22, 3 dropouts; P = 0.038) lost significant amount of weight. The trend of weight changes did not differ between groups (P = 0.530). Subjects from both groups were able to sustain weight loss through 24 weeks (pretzel: 81.43 ± 3.85 kg at baseline vs. 79.43 ± 4.08 kg at week 24, P = 0.028; nut: 84.26 ± 3.78 kg at baseline vs. 82.38 ± 3.72 kg at week 24, P = 0.026). At week 12, fat mass in both groups was significantly decreased (pretzel: P = 0.002; nut: P = 0.012). The trend of fat changes did not differ between groups (P = 0.547). Subjects from both groups were able to sustain fat loss through 24 weeks (pretzel: 30.84 ± 1.75 kg at baseline vs. 29.25 ± 2.12 kg at week 24, P = 0.024; nut: 31.51 ± 1.56 kg vs 30.21 ± 1.81 kg at week 24, P = 0.04). Muscle mass, and blood pressure were not significantly different between both groups. Conclusions Our data suggested that tree nuts could be consumed as part of a healthy weight loss meal plan without concern of causing weight gain. Further analysis of the remaining samples is needed to confirm results. Due to higher dropouts in the pretzel group, future intention-to-treat analysis is also needed to eliminate bias. Funding Sources This study is supported by the International Tree Nut Council.

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Breakfast consumption and weight-loss maintenance: results from the MedWeight study

British Journal Of Nutrition ◽

10.1017/s0007114516001550 ◽

2016 ◽

Vol 115 (12) ◽

pp. 2246-2251 ◽

Cited By ~ 12

Author(s):

Dora Brikou ◽

Dimitra Zannidi ◽

Eleni Karfopoulou ◽

Costas A. Anastasiou ◽

Mary Yannakoulia

Keyword(s):

Weight Loss ◽

Body Weight ◽

Dietary Intake ◽

Eating Behaviour ◽

Weight Loss Maintenance ◽

Precise Definition ◽

Confounding Factors ◽

Initial Body Weight ◽

Breakfast Consumption ◽

At Home

AbstractDaily breakfast consumption is a common eating behaviour among people who have maintained their weight loss after weight-loss management. However, there is not a precise definition for breakfast in the literature. The purpose of this study was to investigate potential associations between breakfast consumption (based on several definitions) and weight-loss maintenance, as well as to explore differences in breakfast quality between individuals who managed to maintain part of the weight loss and in those who regained weight loss. The study sample consisted of 354 participants of the MedWeight study (age: 32 (sd 10) years, 61 % women) who had lost ≥10 % of their initial body weight and either maintained the loss for ≥1 year (maintainers, n 257) or regained weight loss (regainers, n 97). Participants completed online questionnaires and reported their dietary intake through two telephone 24-h recalls. Breakfast consumption was evaluated using twelve different definitions. The analysis indicated that breakfast consumption was associated with weight-loss maintenance only in men, when using self-reported breakfast consumption or the following breakfast definitions: (1) the first eating episode consumed at home and (2) the first eating episode consumed at home excluding caffeinated drinks. This association remained statistically significant even after adjustment for potential confounding factors. Thus, breakfast, the first eating episode of the day, when consumed at home, may be protective against weight regaining.

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Effects of a low carbohydrate diet on energy expenditure during weight loss maintenance: randomized trial

BMJ ◽

10.1136/bmj.k4583 ◽

2018 ◽

pp. k4583 ◽

Cited By ~ 72

Author(s):

Cara B Ebbeling ◽

Henry A Feldman ◽

Gloria L Klein ◽

Julia M W Wong ◽

Lisa Bielak ◽

...

Keyword(s):

Weight Loss ◽

Energy Expenditure ◽

Total Energy ◽

Total Energy Expenditure ◽

Carbohydrate Diet ◽

Intention To Treat ◽

Low Carbohydrate Diet ◽

High Carbohydrate ◽

Low Carbohydrate ◽

Treat Analysis

AbstractObjectiveTo determine the effects of diets varying in carbohydrate to fat ratio on total energy expenditure.DesignRandomized trial.SettingMulticenter collaboration at US two sites, August 2014 to May 2017.Participants164 adults aged 18-65 years with a body mass index of 25 or more.InterventionsAfter 12% (within 2%) weight loss on a run-in diet, participants were randomly assigned to one of three test diets according to carbohydrate content (high, 60%, n=54; moderate, 40%, n=53; or low, 20%, n=57) for 20 weeks. Test diets were controlled for protein and were energy adjusted to maintain weight loss within 2 kg. To test for effect modification predicted by the carbohydrate-insulin model, the sample was divided into thirds of pre-weight loss insulin secretion (insulin concentration 30 minutes after oral glucose).Main outcome measuresThe primary outcome was total energy expenditure, measured with doubly labeled water, by intention-to-treat analysis. Per protocol analysis included participants who maintained target weight loss, potentially providing a more precise effect estimate. Secondary outcomes were resting energy expenditure, measures of physical activity, and levels of the metabolic hormones leptin and ghrelin.ResultsTotal energy expenditure differed by diet in the intention-to-treat analysis (n=162, P=0.002), with a linear trend of 52 kcal/d (95% confidence interval 23 to 82) for every 10% decrease in the contribution of carbohydrate to total energy intake (1 kcal=4.18 kJ=0.00418 MJ). Change in total energy expenditure was 91 kcal/d (95% confidence interval −29 to 210) greater in participants assigned to the moderate carbohydrate diet and 209 kcal/d (91 to 326) greater in those assigned to the low carbohydrate diet compared with the high carbohydrate diet. In the per protocol analysis (n=120, P<0.001), the respective differences were 131 kcal/d (−6 to 267) and 278 kcal/d (144 to 411). Among participants in the highest third of pre-weight loss insulin secretion, the difference between the low and high carbohydrate diet was 308 kcal/d in the intention-to-treat analysis and 478 kcal/d in the per protocol analysis (P<0.004). Ghrelin was significantly lower in participants assigned to the low carbohydrate diet compared with those assigned to the high carbohydrate diet (both analyses). Leptin was also significantly lower in participants assigned to the low carbohydrate diet (per protocol).ConclusionsConsistent with the carbohydrate-insulin model, lowering dietary carbohydrate increased energy expenditure during weight loss maintenance. This metabolic effect may improve the success of obesity treatment, especially among those with high insulin secretion.Trial registrationClinicalTrials.govNCT02068885.

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Beyond Body Weight-Loss: Dietary Strategies Targeting Intrahepatic Fat in NAFLD

Nutrients ◽

10.3390/nu12051316 ◽

2020 ◽

Vol 12 (5) ◽

pp. 1316 ◽

Cited By ~ 4

Author(s):

Nicolai Worm

Keyword(s):

Insulin Resistance ◽

Weight Loss ◽

Body Weight ◽

Liver Disease ◽

Glycogen Synthesis ◽

Liver Fat ◽

Meal Replacement ◽

Alcoholic Fatty Liver ◽

Therapeutic Concept ◽

The Metabolic Syndrome

Non-alcoholic fatty liver disease (NAFLD) has emerged as the most prevalent liver disease in industrialized countries. It is regarded as the hepatic manifestation of the metabolic syndrome (MetS) resulting from insulin resistance. Moreover, insulin resistance impairs glycogen synthesis, postprandially diverting a substantial amount of carbohydrates to the liver and storing them there as fat. NAFLD has far-reaching metabolic consequences involving glucose and lipoprotein metabolism disorders and risk of cardiovascular disease, the leading cause of death worldwide. No pharmaceutical options are currently approved for the treatment of NAFLD. Exercise training and dietary interventions remain the cornerstone of NAFLD treatment. Current international guidelines state that the primary goal of nutritional therapy is to reduce energy intake to achieve a 7%–10% reduction in body weight. Meal replacement therapy (formula diets) results in more pronounced weight loss compared to conventional calorie-restricted diets. However, studies have shown that body mass index (BMI) or weight reduction is not obligatory for decreasing hepatic fat content or to restore normal liver function. Recent studies have achieved significant reductions in liver fat with eucaloric diets and without weight loss through macronutrient modifications. Based on this evidence, an integrative nutritional therapeutic concept was formulated that combines the most effective nutrition approaches termed “liver-fasting.” It involves the temporary use of a low calorie diet (total meal replacement with a specific high-protein, high-soluble fiber, lower-carbohydrate formula), followed by stepwise food reintroduction that implements a Mediterranean style low-carb diet as basic nutrition.

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Effect of the Mediterranean diet with and without weight loss on surrogate markers of cholesterol homeostasis in men with the metabolic syndrome

British Journal Of Nutrition ◽

10.1017/s0007114511003436 ◽

2011 ◽

Vol 107 (5) ◽

pp. 705-711 ◽

Cited By ~ 43

Author(s):

Caroline Richard ◽

Patrick Couture ◽

Sophie Desroches ◽

Suzanne Benjannet ◽

Nabil G. Seidah ◽

...

Keyword(s):

Metabolic Syndrome ◽

Weight Loss ◽

Body Weight ◽

Control Diet ◽

Cholesterol Absorption ◽

Energy Restriction ◽

Surrogate Markers ◽

The Metabolic Syndrome ◽

The Mediterranean ◽

The Impact

The mechanisms implicated in the LDL-cholesterol (LDL-C)-lowering effects of the Mediterranean-type diet (MedDiet) are unknown. The present study assessed the impact of the MedDiet consumed under controlled feeding conditions, with and without weight loss, on surrogate markers of cholesterol absorption, synthesis and clearance using plasma phytosterols, lathosterol and proprotein convertase subtilisin/kexin-9 (PCSK9) concentrations, respectively, in men with the metabolic syndrome. The subjects' diet (n19, 24–62 years) was first standardised to a baseline North American control diet (5 weeks) followed by a MedDiet (5 weeks), both under weight-maintaining isoenergetic feeding conditions. The participants then underwent a 20-week free-living energy restriction period (10 (sd3) % reduction in body weight,P < 0·01), followed by the consumption of the MedDiet (5 weeks) under controlled isoenergetic feeding conditions. The LDL-C-lowering effect of the MedDiet in the absence of weight loss ( − 9·9 %) was accompanied by significant reductions in plasma PCSK9 concentrations ( − 11·7 %,P < 0·01) and in the phytosterol:cholesterol ratio ( − 9·7 %,P < 0·01) compared with the control diet. The addition of weight loss to the MedDiet had no further impact on plasma LDL-C concentrations and on these surrogate markers of LDL clearance and cholesterol absorption. The present results suggest that the MedDiet reduces plasma LDL-C concentrations primarily by increasing LDL clearance and reducing cholesterol absorption, with no synergistic effect of body weight loss in this process.

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Modeling weight-loss maintenance to help prevent body weight regain

American Journal of Clinical Nutrition ◽

10.3945/ajcn.2008.26333 ◽

2008 ◽

Vol 88 (6) ◽

pp. 1495-1503 ◽

Cited By ~ 64

Author(s):

Kevin D Hall ◽

Peter N Jordan

Keyword(s):

Weight Loss ◽

Body Weight ◽

Weight Regain ◽

Weight Loss Maintenance

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Very Low and Higher Carbohydrate Diets Promote Differential Appetite Responses in Adults with Type 2 Diabetes: A Randomized Trial

Journal of Nutrition ◽

10.1093/jn/nxz344 ◽

2020 ◽

Vol 150 (4) ◽

pp. 800-805

Author(s):

Noor A Struik ◽

Grant D Brinkworth ◽

Campbell H Thompson ◽

Jonathan D Buckley ◽

Gary Wittert ◽

...

Keyword(s):

Type 2 Diabetes ◽

Body Weight ◽

Repeated Measures ◽

Secondary Analysis ◽

Saturated Fat ◽

Energy Restriction ◽

E Protein ◽

Low Carbohydrate ◽

Prospective Consumption

ABSTRACT Background Effects of very low carbohydrate (VLC) diets on appetite response in individuals with type 2 diabetes remain unclear. Objective A secondary analysis was conducted to determine appetite responses to an energy-restricted [30% of energy (%E) deficit] very low carbohydrate (VLC) diet compared with a higher carbohydrate (HC) diet in adults who were overweight or obese with type 2 diabetes. Methods Forty-four men and 40 women (mean ± SD, age: 58.7 ± 6.6 y; weight: 100.4 ± 15.5 kg; BMI: 34.5 ± 4.1 kg/m2; glycated hemoglobin: 7.3 ± 1.0%; duration of diabetes: 6.7 ± 5.6 y) were randomly assigned to diets categorized as VLC [14%E carbohydrate (<50 g/d), 28%E protein, 58%E fat (<10%E saturated fat)], or energy-matched HC [53%E carbohydrate, 17%E protein, 30%E fat (<10%E saturated fat)] combined with progressive multicomponent exercise (60 min; 3 d/wk). Body weight, average weekly “daily fasting” and “daily overall” appetite perceptions (hunger, fullness, prospective consumption, and desire to eat—visual analog scales) were assessed at baseline and after 4 and 16 wk. Changes between diets over time were assessed using repeated measures ANOVA. Results Significant decreases in body weight did not differ between groups (VLC: −11.0 ± 5.4 kg/16 wk compared with HC: −10.1 ± 4.3 kg/16 wk, P = 0.40). Compared with HC, VLC had greater decreases in “daily overall” ratings of fullness (P time × diet < 0.01), such that scores were higher in HC at Week 4 (VLC:48 ± 3 vs HC:56 ± 3 mm, P = 0.001) and 16 (VLC:51 ± 2 vs HC:57 ± 3 mm, P = 0.019). Compared with HC, VLC had greater increases in prospective consumption ratings (P time × diet = 0.03), such that scores were lower in HC at Week 4 (VLC:33 ± 2 vs HC:28 ± 2 mm, P = 0.008), but not at Week 16 (VLC:33 ± 2 vs HC 31 ± 2 mm, P = 0.289). Conclusions In the context of energy restriction, both HC and VLC energy-matched diets promoted comparable effects on fasting perceptions of appetite, but the HC diet resulted in greater “daily overall” fullness and reduced prospective consumption. Further research is required to evaluate the effects of ad libitum diets differing in amounts of carbohydrate on appetite response in populations with type 2 diabetes. This trial was registered at www.anzctr.org.au as ACTRN12612000369820.

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Low Carbohydrate and Low-Fat Diets: What We Don't Know and Why we Should Know It

Nutrients ◽

10.3390/nu11112749 ◽

2019 ◽

Vol 11 (11) ◽

pp. 2749 ◽

Cited By ~ 6

Author(s):

Seid ◽

Rosenbaum

Keyword(s):

Weight Loss ◽

Weight Maintenance ◽

Caloric Intake ◽

Saturated Fat ◽

Conclusive Evidence ◽

Low Fat ◽

Low Carbohydrate Diet ◽

Low Fat Diet ◽

Low Carbohydrate ◽

Cholesterol Intake

In the 1940s, the diet-heart hypothesis proposed that high dietary saturated fat and cholesterol intake promoted coronary heart disease in “at-risk“ individuals. This hypothesis prompted federal recommendations for a low-fat diet for “high risk” patients and as a preventive health measure for everyone except infants. The low carbohydrate diet, first used to treat type 1 diabetes, became a popular obesity therapy with the Atkins diet in the 1970s. Its predicted effectiveness was based largely on the hypothesis that insulin is the causa prima of weight gain and regain via hyperphagia and hypometabolism during and after weight reduction, and therefore reduced carbohydrate intake would promote and sustain weight loss. Based on literature reviews, there are insufficient randomized controlled inpatient studies examining the physiological significance of the mechanisms proposed to support one over the other. Outpatient studies can be confounded by poor diet compliance such that the quality and quantity of the energy intake cannot be ascertained. Many studies also fail to separate macronutrient quantity from quality. Overall, there is no conclusive evidence that the degree of weight loss or the duration of reduced weight maintenance are significantly affected by dietary macronutrient quantity beyond effects attributable to caloric intake. Further work is needed.

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