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Consuming a hypocaloric high fat low carbohydrate diet for 12 weeks lowers C-reactive protein, and raises serum adiponectin and high density lipoprotein-cholesterol in obese subjects

URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3845365/

Journal: Metabolism

Publication Date: 12/2013

Summary: High fat, low carbohydrate (HFLC) diets have become popular tools for weight management. We sought to determine the effects of a HFLC diet compared to a low fat high carbohydrate (LFHC) diet on the change in weight loss, cardiovascular risk factors and inflammation in subjects with obesity. Obese subjects (29.0–44.6 kg/m2) recruited from Boston Medical Center were randomized to a hypocaloric LFHC (n=26) or HFLC (n=29) diet for 12 weeks. The age range of subjects was 21–62 years. As a percentage of daily calories, the HFLC group consumed 33.5% protein, 56.0% fat and 9.6% carbohydrate and the LFHC group consumed 22.0% protein, 25.0% fat and 55.7% carbohydrate. The change in percent body weight, lean and fat mass, blood pressure, flow mediated dilation, hip:waist ratio, hemoglobin A1C, fasting insulin and glucose, and glucose and insulin response to a 2 h oral glucose tolerance test did not differ (P>0.05) between diets after 12 weeks. The HFLC group had greater mean decreases in serum triglyceride (P=0.07), and hs-CRP (P=0.03), and greater mean increases in HDL cholesterol (P=0.004), and total adiponectin (P=0.045) relative to the LFHC. Secreted adipose tissue adiponectin or TNF-α did not differ after weight loss for either diet. Relative to the LFHC group, the HFLC group had greater improvements in blood lipids and systemic inflammation with similar changes in body weight and composition. This small-scale study suggests that HFLC diets may be more beneficial to cardiovascular health and inflammation in free-living obese adults compared to LFHC diets.

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Beyond weight loss: a review of the therapeutic uses of very-low-carbohydrate (ketogenic) diets

URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3826507/

Journal: European Journal of Clinical Nutrition

Publication Date: 08/2013

Summary: Very-low-carbohydrate diets or ketogenic diets have been in use since the 1920s as a therapy for epilepsy and can, in some cases, completely remove the need for medication. From the 1960s onwards they have become widely known as one of the most common methods for obesity treatment. Recent work over the last decade or so has provided evidence of the therapeutic potential of ketogenic diets in many pathological conditions, such as diabetes, polycystic ovary syndrome, acne, neurological diseases, cancer and the amelioration of respiratory and cardiovascular disease risk factors. The possibility that modifying food intake can be useful for reducing or eliminating pharmaceutical methods of treatment, which are often lifelong with significant side effects, calls for serious investigation. This review revisits the meaning of physiological ketosis in the light of this evidence and considers possible mechanisms for the therapeutic actions of the ketogenic diet on different diseases. The present review also questions whether there are still some preconceived ideas about ketogenic diets, which may be presenting unnecessary barriers to their use as therapeutic tools in the physician’s hand.

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Ketosis and appetite-mediating nutrients and hormones after weight loss

URL: https://www.nature.com/articles/ejcn201390

Journal: European Journal of Clinical Nutrition

Publication Date: 05/2013

Summary: Diet-induced weight loss is accompanied by compensatory changes, which increase appetite and encourage weight regain. There is some evidence that ketogenic diets suppress appetite. The objective is to examine the effect of ketosis on a number of circulating factors involved in appetite regulation, following diet-induced weight loss. Of 50 non-diabetic overweight or obese subjects who began the study, 39 completed an 8-week ketogenic very-low-energy diet (VLED), followed by 2 weeks of reintroduction of foods. Following weight loss, circulating concentrations of glucose, insulin, non-esterified fatty acids (NEFA), β-hydroxybutyrate (BHB), leptin, gastrointestinal hormones and subjective ratings of appetite were compared when subjects were ketotic, and after refeeding. During the ketogenic VLED, subjects lost 13% of initial weight and fasting BHB increased from (mean±s.e.m.) 0.07±0.00 to 0.48±0.07 mmol/l (P<0.001). BHB fell to 0.19±0.03 mmol/l after 2 weeks of refeeding (P<0.001 compared with week 8). When participants were ketotic, the weight loss induced increase in ghrelin was suppressed. Glucose and NEFA were higher, and amylin, leptin and subjective ratings of appetite were lower at week 8 than after refeeding. The circulating concentrations of several hormones and nutrients which influence appetite were altered after weight loss induced by a ketogenic diet, compared with after refeeding. The increase in circulating ghrelin and subjective appetite which accompany dietary weight reduction were mitigated when weight-reduced participants were ketotic.

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Improvements in Glucose Metabolism and Insulin Sensitivity with a Low-Carbohydrate Diet in Obese Patients with Type 2 Diabetes

URL: https://www.ncbi.nlm.nih.gov/pubmed/24015695

Journal: Journal of the American College of Nutrition

Publication Date: 04/2013

Summary: The optimal diet for weight loss in type 2 diabetes remains controversial. This study examined a low-carbohydrate, high-fat diet with detailed physiological assessments of insulin sensitivity, glycemic control, and risk factors for cardiovascular disease. Fourteen obese patients (body mass index [BMI] 40.6 ± 4.9 kg/m2) with type 2 diabetes were recruited for an “Atkins”-type low-carbohydrate diet. Measurements were made at 0, 12, and 24 weeks of weight, insulin sensitivity, HbA1c, lipids, and blood pressure. Twelve completers lost a mean of 9.7 ± 1.8 kg over 24 weeks attributable to a major reduction in carbohydrates and resultant reduction in total energy intake. Glycemic control significantly improved (HbA1c −1.1 ± 0.25%) with reductions in hypoglycemic medication. Fasting glucose, homeostasis model assessment (HOMA), and area under the curve (AUC) glucose (intravenous glucose tolerance test [IVGTT]) were significantly reduced by week 12 (p < 0.05). There were nonsignificant improvements in insulin sensitivity (SI) at week 12 ( p = 0.19) and week 24 ( p = 0.31). Systolic blood pressure was reduced (mean −10.0 mmHg between weeks 0 and 24, p = 0.13). Mean high-density lipoprotein (HDL), low-density lipoprotein (LDL), and total cholesterol all increased. The ratio of total: HDL cholesterol and triglycerides was reduced. A low-carbohydrate diet was well tolerated and achieved weight loss over 24 weeks in subjects with diabetes. Glycemic control improved with a reduction in requirements for hypoglycemic agents.

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Dietary carbohydrate restriction as the first approach in diabetes management: Critical review and evidence base

URL: https://www.sciencedirect.com/science/article/pii/S0899900714003323?via%3Dihub

Journal: Nutrition

Publication Date: 01/2015

Summary: The inability of current recommendations to control the epidemic of diabetes, the specific failure of the prevailing low-fat diets to improve obesity, cardiovascular risk, or general health and the persistent reports of some serious side effects of commonly prescribed diabetic medications, in combination with the continued success of low-carbohydrate diets in the treatment of diabetes and metabolic syndromewithout significant side effects, point to the need for a reappraisal of dietary guidelines. The benefits of carbohydrate restriction in diabetes are immediate and well documented. Concerns about the efficacy and safety are long term and conjectural rather than data driven. Dietary carbohydrate restriction reliably reduces high blood glucose, does not require weight loss (although is still best for weight loss), and leads to the reduction or elimination of medication. It has never shown side effects comparable with those seen in many drugs. Here we present 12 points of evidence supporting the use of low-carbohydrate diets as the first approach to treating type 2 diabetes and as the most effective adjunct to pharmacology in type 1. They represent the best-documented, least controversial results. The insistence on long-term randomized controlled trials as the only kind of data that will be accepted is without precedent in science. The seriousness of diabetes requires that we evaluate all of the evidence that is available. The 12 points are sufficiently compelling that we feel that the burden of proof rests with those who are opposed.

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Diets with high-fat cheese, high-fat meat, or carbohydrate on cardiovascular risk markers in overweight postmenopausal women: a randomized crossover trial.

URL: https://www.ncbi.nlm.nih.gov/pubmed/26178720

Journal: American Journal of Clinical Nutrition

Publication Date: 09/2015

Summary: Heart associations recommend limited intake of saturated fat. However, effects of saturated fat on low-density lipoprotein (LDL)-cholesterol concentrations and cardiovascular disease risk might depend on nutrients and specific saturated fatty acids (SFAs) in food. We explored the effects of cheese and meat as sources of SFAs or isocaloric replacement with carbohydrates on blood lipids, lipoproteins, and fecal excretion of fat and bile acids. The study was a randomized, crossover, open-label intervention in 14 overweight postmenopausal women. Three full-diet periods of 2-wk duration were provided separated by 2-wk washout periods. The isocaloric diets were as follows: 1) a high-cheese (96-120-g) intervention [i.e., intervention containing cheese (CHEESE)], 2) a macronutrient-matched nondairy, high-meat control [i.e., nondairy control with a high content of high-fat processed and unprocessed meat in amounts matching the saturated fat content from cheese in the intervention containing cheese (MEAT)], and 3) a nondairy, low-fat, high-carbohydrate control (i.e., nondairy low-fat control in which the energy from cheese fat and protein was isocalorically replaced by carbohydrates and lean meat (CARB). The CHEESE diet caused a 5% higher high-density lipoprotein (HDL)-cholesterol concentration (P = 0.012), an 8% higher apo A-I concentration (P < 0.001), and a 5% lower apoB:apo A-I ratio (P = 0.008) than did the CARB diet. Also, the MEAT diet caused an 8% higher HDL-cholesterol concentration (P < 0.001) and a 4% higher apo A-I concentration (P = 0.033) than did the CARB diet. Total cholesterol, LDL cholesterol, apoB, and triacylglycerol were similar with the 3 diets. Fecal fat excretion was 1.8 and 0.9 g higher with the CHEESE diet than with CARB and MEAT diets (P < 0.001 and P = 0.004, respectively) and 0.9 g higher with the MEAT diet than with the CARB diet (P = 0.005). CHEESE and MEAT diets caused higher fecal bile acid excretion than did the CARB diet (P < 0.05 and P = 0.006, respectively). The dominant type of bile acids excreted differed between CHEESE and MEAT diets. Diets with cheese and meat as primary sources of SFAs cause higher HDL cholesterol and apo A-I and, therefore, appear to be less atherogenic than is a low-fat, high-carbohydrate diet. Also, our findings confirm that cheese increases fecal fat excretion.

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Do ketogenic diets really suppress appetite? A systematic review and meta-analysis.

URL: https://www.ncbi.nlm.nih.gov/pubmed/25402637

Journal: Obesity Reviews

Publication Date: 01/2015

Summary: Very-low-energy diets (VLEDs) and ketogenic low-carbohydrate diets (KLCDs) are two dietary strategies that have been associated with a suppression of appetite. However, the results of clinical trials investigating the effect of ketogenic diets on appetite are inconsistent. To evaluate quantitatively the effect of ketogenic diets on subjective appetite ratings, we conducted a systematic literature search and meta-analysis of studies that assessed appetite with visual analogue scales before (in energy balance) and during (while in ketosis) adherence to VLED or KLCD. Individuals were less hungry and exhibited greater fullness/satiety while adhering to VLED, and individuals adhering to KLCD were less hungry and had a reduced desire to eat. Although these absolute changes in appetite were small, they occurred within the context of energy restriction, which is known to increase appetite in obese people. Thus, the clinical benefit of a ketogenic diet is in preventing an increase in appetite, despite weight loss, although individuals may indeed feel slightly less hungry (or more full or satisfied). Ketosis appears to provide a plausible explanation for this suppression of appetite. Future studies should investigate the minimum level of ketosis required to achieve appetite suppression during ketogenic weight loss diets, as this could enable inclusion of a greater variety of healthy carbohydrate-containing foods into the diet.

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A randomized pilot study comparing zero-calorie alternate-day fasting to daily caloric restriction in adults with obesity.

URL: https://www.ncbi.nlm.nih.gov/pubmed/27569118

Journal: Obesity

Publication Date: 09/2016

Summary: To evaluate the safety and tolerability of alternate-day fasting (ADF) and to compare changes in weight, body composition, lipids, and insulin sensitivity index (Si) with those produced by a standard weight loss diet, moderate daily caloric restriction (CR). Adults with obesity (BMI ≥30 kg/m(2) , age 18-55) were randomized to either zero-calorie ADF (n = 14) or CR (-400 kcal/day, n = 12) for 8 weeks. Outcomes were measured at the end of the 8-week intervention and after 24 weeks of unsupervised follow-up. No adverse effects were attributed to ADF, and 93% completed the 8-week ADF protocol. At 8 weeks, ADF achieved a 376 kcal/day greater energy deficit; however, there were no significant between-group differences in change in weight (mean ± SE; ADF -8.2 ± 0.9 kg, CR -7.1 ± 1.0 kg), body composition, lipids, or Si. After 24 weeks of unsupervised follow-up, there were no significant differences in weight regain; however, changes from baseline in % fat mass and lean mass were more favorable in ADF. ADF is a safe and tolerable approach to weight loss. ADF produced similar changes in weight, body composition, lipids, and Si at 8 weeks and did not appear to increase risk for weight regain 24 weeks after completing the intervention.

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Very low-calorie ketogenic diet may allow restoring response to systemic therapy in relapsing plaque psoriasis.

URL: https://www.ncbi.nlm.nih.gov/pubmed/26559897

Journal: Obesity Research & Clinical Practice

Publication Date: 05/2016

Summary: Psoriasis is a chronic disease associated with overweight/obesity and related cardiometabolic complications. The link between these diseases is likely the inflammatory background associated with adipose tissue, particularly the vis- ceral one. Accordingly, previous studies have demonstrated that in the long-term weight loss may improve the response to systemic therapies. We report a case report of a woman in her 40s suffering from relapsing moderate-to-severe plaque psoriasis and obesity-related metabolic syndrome, in whom adequate response to ongoing treatment with biological therapy (adalimumab) was restored after only 4 weeks of very low-calorie, carbohydrate-free (ketogenic), protein-based diet. Accordingly, through rapid and consistent weight loss, very low calorie ketogenic diet may allow restoring a quick response to systemic therapy in a patient suffering from relaps- ing psoriasis. This intervention should be considered in overweight/obese patients before the rearrangement of systemic therapy. Nonetheless, studies are required to evaluate whether very low calorie ketogenic diets should be preferred to common low-calorie diets to improve the response to systemic therapy at least in patients with moderate-to-severe psoriasis.

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Effects of eight weeks of time-restricted feeding (16/8) on basal metabolism, maximal strength, body composition, inflammation, and cardiovascular risk factors in resistance-trained males.

URL: https://www.ncbi.nlm.nih.gov/pubmed/27737674

Journal: Journal of Translational Medicine

Publication Date: 10/2016

Summary: Intermittent fasting (IF) is an increasingly popular dietary approach used for weight loss and overall health. While there is an increasing body of evidence demonstrating beneficial effects of IF on blood lipids and other health outcomes in the overweight and obese, limited data are available about the effect of IF in athletes. Thus, the present study sought to investigate the effects of a modified IF protocol (i.e. time-restricted feeding) during resistance training in healthy resistance-trained males. Thirty-four resistance-trained males were randomly assigned to time-restricted feeding (TRF) or normal diet group (ND). TRF subjects consumed 100 % of their energy needs in an 8-h period of time each day, with their caloric intake divided into three meals consumed at 1 p.m., 4 p.m., and 8 p.m. The remaining 16 h per 24-h period made up the fasting period. Subjects in the ND group consumed 100 % of their energy needs divided into three meals consumed at 8 a.m., 1 p.m., and 8 p.m. Groups were matched for kilocalories consumed and macronutrient distribution (TRF 2826 ± 412.3 kcal/day, carbohydrates 53.2 ± 1.4 %, fat 24.7 ± 3.1 %, protein 22.1 ± 2.6 %, ND 3007 ± 444.7 kcal/day, carbohydrates 54.7 ± 2.2 %, fat 23.9 ± 3.5 %, protein 21.4 ± 1.8). Subjects were tested before and after 8 weeks of the assigned diet and standardized resistance training program. Fat mass and fat-free mass were assessed by dual-energy x-ray absorptiometry and muscle area of the thigh and arm were measured using an anthropometric system. Total and free testosterone, insulin-like growth factor 1, blood glucose, insulin, adiponectin, leptin, triiodothyronine, thyroid stimulating hormone, interleukin-6, interleukin-1β, tumor necrosis factor α, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides were measured. Bench press and leg press maximal strength, resting energy expenditure, and respiratory ratio were also tested. After 8 weeks, the 2 Way ANOVA (Time * Diet interaction) showed a decrease in fat mass in TRF compared to ND (p = 0.0448), while fat-free mass, muscle area of the arm and thigh, and maximal strength were maintained in both groups. Testosterone and insulin-like growth factor 1 decreased significantly in TRF, with no changes in ND (p = 0.0476; p = 0.0397). Adiponectin increased (p = 0.0000) in TRF while total leptin decreased (p = 0.0001), although not when adjusted for fat mass. Triiodothyronine decreased in TRF, but no significant changes were detected in thyroid-stimulating hormone, total cholesterol, high-density lipoprotein, low-density lipoprotein, or triglycerides. Resting energy expenditure was unchanged, but a significant decrease in respiratory ratio was observed in the TRF group. Our results suggest that an intermittent fasting program in which all calories are consumed in an 8-h window each day, in conjunction with resistance training, could improve some health-related biomarkers, decrease fat mass, and maintain muscle mass in resistance-trained males.