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Comparing the Effects of Consuming Almonds or Biscuits on Body Weight in Habitual Snackers: A 1-Year Randomized Controlled Trial.
Brown, RC, Ware, L, Gray, AR, Tey, SL, Chisholm, A
The American journal of clinical nutrition. 2023;118(1):228-240
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Snacking has been implicated in a possible reason for many individuals consuming excess calories in their diet and weight gain. However, it has been suggested that not all snacks are not equal or responsible for weight gain. Nuts are high in fat and energy dense, however regular nut consumers are leaner than non-consumers and regular consumption has been shown to result in either no weight gain or less weight gain than should be seen. This randomised control trial aimed to determine the effects of long-term consumption of almonds compared with biscuits. The results showed that neither biscuits nor almonds resulted in a greater amount of weight gain and neither affected blood lipid or sugar levels more than the other. Nut consumption did however improve nutrient intakes and diet quality with increased protein, fat, vitamin E, calcium, copper, magnesium, phosphorous, and zinc. Carbohydrate and sugar intake was also decreased when almonds were the snack. It was concluded that the incorporation of almonds into the diet by habitual snackers improved diet quality without affecting body weight or body composition compared to a biscuit snack. This study could be used by healthcare professionals to encourage snackers to switch from a high energy, low nutrient snack such as biscuits to nuts to improve diet quality and nutrient intakes.
Abstract
BACKGROUND Almonds are nutrient rich, providing a healthier alternative to many snacks. Studies report health benefits with regular almond consumption without adverse weight gain. However, most interventions have been relatively short or have included additional dietary advice. OBJECTIVES Taking a pragmatic approach, we compared consumption of almonds compared with biscuits on body weight and other health outcomes in a population of regular snackers of discretionary foods, hypothesizing the almonds will displace some of the less-healthful snacks in their current diets. METHODS We randomly assigned 136 nonobese habitual discretionary snackers to receive almonds or biscuits daily for 1 y. These isocaloric snacks provided either 10% of participants' total energy (TE) requirements or 1030 kJ (equivalent to 42.5 g almonds), whichever was greater. Anthropometry, blood biomarkers, diet, appetite, sleep, and physical activity were assessed at baseline, 3, 6, and 12 mo, and body composition and RMR at baseline and 12 mo. RESULTS The difference in changes for body weight from baseline to 12 mo was not statistically significant (geometric means: 67.1 and 69.5 kg for almonds and 66.3 and 66.3 kg for biscuits, P = 0.275). There were no statistically significant differences in changes for body composition or other nondietary outcomes (all P ≥ 0.112). Absolute intakes of protein; total, polyunsaturated, and monosaturated fat; fiber; vitamin E; calcium; copper; magnesium; phosphorous; and zinc, and % TE from total monounsaturated, and polyunsaturated fat statistically significantly increased from baseline (all P ≤ 0.033), whereas % TE from carbohydrate and sugar statistically significantly (both P ≤ 0.014) decreased from baseline, in the almond compared with the biscuit group. CONCLUSIONS Almonds can be incorporated into the diets of habitual snackers to improve diet quality, without evidence for changes in body weight, compared with a popular discretionary snack food. This trial was registered at the Australian New Zealand Clinical Trials Registry (https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=375610&isReview=true), registration number ACTRN12618001758291.
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Could the ketogenic diet induce a shift in thyroid function and support a metabolic advantage in healthy participants? A pilot randomized-controlled-crossover trial.
Iacovides, S, Maloney, SK, Bhana, S, Angamia, Z, Meiring, RM
PloS one. 2022;17(6):e0269440
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The ketogenic diet (KD) has been shown in several studies to result in weight loss compared to a conventional high-carbohydrate, low-fat diet (HCLF). It is thought that this sort of diet may inhibit the appetite and increase feelings of being fuller for longer. However, its effects on other biological functions which can lead to weight loss are unclear. This randomised control trial of 11 individuals aimed to determine the effect of the KD on thyroid function, which controls the conversion of calories into energy and therefore has a role in fat storage. The results showed that KD resulted in a higher loss of body mass than the HCLF diet and one of the thyroid hormones (T3) was decreased. However, hormones which stimulate thyroid function remained unchanged. It was concluded that changes in metabolism can occur following the KD, which may contribute to a greater loss of weight compared to a HCLF diet. This study could be used by healthcare professionals to understand that the ketogenic diet may be more effective at weight loss than a standard HCLF diet. However larger scale trials are warranted.
Abstract
BACKGROUND The ketogenic diet (KD) has been shown to result in body mass loss in people with disease as well as healthy people, yet the effect of the KD on thyroid function and metabolism are unknown. OBJECTIVE We aimed to determine the effects of a KD, compared with an isocaloric high-carbohydrate low-fat (HCLF) diet, on resting metabolic rate and thyroid function in healthy individuals. DESIGN Eleven healthy, normal-weight participants (mean(SD) age: 30(9) years) completed this randomized crossover-controlled study. For a minimum of three weeks on each, participants followed two isocaloric diets: a HCLF diet (55%carbohydrate, 20%fat, 25%protein) and a KD (15%carbohydrate, 60%fat, 25% protein), with a one-week washout period in-between. Importantly, while on the KD, the participants were required to remain in a state of nutritional ketosis for three consecutive weeks. Crossover analyses and linear mixed models were used to assess effect of diet on body mass, thyroid function and resting metabolic rate. RESULTS Both dietary interventions resulted in significant body mass loss (p<0.05) however three weeks of sustained ketosis (KD) resulted in a greater loss of body mass (mean (95%CI): -2.9 (-3.5, -2.4) kg) than did three weeks on the HCLF diet (-0.4 (-1.0, 0.1) kg, p < 0.0001). Compared to pre-diet levels, the change in plasma T3 concentration was significantly different between the two diets (p = 0.003), such that plasma T3 concentration was significantly lower following the KD diet (4.1 (3.8, 4.4) pmol/L, p<0.0001) but not different following the HCLF diet (4.8 (4.5, 5.2) pmol/L, p = 0.171. There was a significant increase in T4 concentration from pre-diet levels following the KD diet (19.3 (17.8, 20.9) pmol/L, p < 0.0001), but not following the HCLF diet (17.3 (15.7, 18.8) pmol.L, p = 0.28). The magnitude of change in plasma T4 concentration was not different between the two diets (p = 0.4). There was no effect of diet on plasma thyroid stimulating hormone concentration (p = 0.27). There was a significantly greater T3:T4 ratio following the HCLF diet (0.41 (0.27, 0.55), p < 0.0001) compared to pre-diet levels but not following the KD diet (0.25 (0.12, 0.39), p = 0.80). CONCLUSIONS Although the diets were isocaloric and physical activity and resting metabolic rate remained constant, the participants lost more mass after the KD than after the HCLF diet. The observed significant changes in triiodothyronine concentration suggest that unknown metabolic changes occur in nutritional ketosis, changes that warrant further investigation. TRIAL REGISTRATION Pan African Clinical Trial Registry: PACTR201707002406306 URL: https://pactr.samrc.ac.za/.
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The effect of morning vs evening exercise training on glycaemic control and serum metabolites in overweight/obese men: a randomised trial.
Moholdt, T, Parr, EB, Devlin, BL, Debik, J, Giskeødegård, G, Hawley, JA
Diabetologia. 2021;64(9):2061-2076
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Timing of exercise, whether morning or evening, may have differing effects on blood sugar control. However, it is unclear as to the exact effects with some previous research reporting that morning exercise is more beneficial to blood sugar levels and others reporting that evening exercise is. This 12-week randomised control trial of 25 overweight/obese men aimed to determine the effect of a 6-day high fat diet followed by 5 days of either morning or evening exercise on several health measures, including blood sugar. The results showed that improvements to heart and lung fitness were similar regardless of the timing of exercise, however improvements to blood sugar and reversal of several indicators of poor heart health were only observed when participants engaged in evening exercise. It was concluded that late afternoon/evening exercise may be of greater benefit to health. This study could be used by healthcare professionals to recommend evening as an optimal time to exercise for people who are overweight/obese and who are wanting to confer the greatest benefits to their health.
Abstract
AIMS/HYPOTHESIS We determined whether the time of day of exercise training (morning vs evening) would modulate the effects of consumption of a high-fat diet (HFD) on glycaemic control, whole-body health markers and serum metabolomics. METHODS In this three-armed parallel-group randomised trial undertaken at a university in Melbourne, Australia, overweight/obese men consumed an HFD (65% of energy from fat) for 11 consecutive days. Participants were recruited via social media and community advertisements. Eligibility criteria for participation were male sex, age 30-45 years, BMI 27.0-35.0 kg/m2 and sedentary lifestyle. The main exclusion criteria were known CVD or type 2 diabetes, taking prescription medications, and shift-work. After 5 days, participants were allocated using a computer random generator to either exercise in the morning (06:30 hours), exercise in the evening (18:30 hours) or no exercise for the subsequent 5 days. Participants and researchers were not blinded to group assignment. Changes in serum metabolites, circulating lipids, cardiorespiratory fitness, BP, and glycaemic control (from continuous glucose monitoring) were compared between groups. RESULTS Twenty-five participants were randomised (morning exercise n = 9; evening exercise n = 8; no exercise n = 8) and 24 participants completed the study and were included in analyses (n = 8 per group). Five days of HFD induced marked perturbations in serum metabolites related to lipid and amino acid metabolism. Exercise training had a smaller impact than the HFD on changes in circulating metabolites, and only exercise undertaken in the evening was able to partly reverse some of the HFD-induced changes in metabolomic profiles. Twenty-four-hour glucose concentrations were lower after 5 days of HFD compared with the participants' habitual diet (5.3 ± 0.4 vs 5.6 ± 0.4 mmol/l, p = 0.001). There were no significant changes in 24 h glucose concentrations for either exercise group but lower nocturnal glucose levels were observed in participants who trained in the evening, compared with when they consumed the HFD alone (4.9 ± 0.4 vs 5.3 ± 0.3 mmol/l, p = 0.04). Compared with the no-exercise group, peak oxygen uptake improved after both morning (estimated effect 1.3 ml min-1 kg-1 [95% CI 0.5, 2.0], p = 0.003) and evening exercise (estimated effect 1.4 ml min-1 kg-1 [95% CI 0.6, 2.2], p = 0.001). Fasting blood glucose, insulin, cholesterol, triacylglycerol and LDL-cholesterol concentrations decreased only in participants allocated to evening exercise training. There were no unintended or adverse effects. CONCLUSIONS/INTERPRETATION A short-term HFD in overweight/obese men induced substantial alterations in lipid- and amino acid-related serum metabolites. Improvements in cardiorespiratory fitness were similar regardless of the time of day of exercise training. However, improvements in glycaemic control and partial reversal of HFD-induced changes in metabolic profiles were only observed when participants exercise trained in the evening. TRIAL REGISTRATION anzctr.org.au registration no. ACTRN12617000304336. FUNDING This study was funded by the Novo Nordisk Foundation (NNF14OC0011493).
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Gastric emptying of solutions containing the natural sweetener erythritol and effects on gut hormone secretion in humans: A pilot dose-ranging study.
Wölnerhanssen, BK, Drewe, J, Verbeure, W, le Roux, CW, Dellatorre-Teixeira, L, Rehfeld, JF, Holst, JJ, Hartmann, B, Tack, J, Peterli, R, et al
Diabetes, obesity & metabolism. 2021;23(6):1311-1321
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In recent years, erythritol, a non-calorie sweetener, has gained popularity due to the rise in obesity and Type 2 diabetes worldwide. The purpose of this randomised, placebo-controlled, double-blind, cross-over trial was to assess the effects of erythritol on the release of gut hormones, speed of gastric emptying, and the release of glucagon, motilin, and glucose-dependent insulinotropic polypeptide after erythritol administration. Erythritol in doses of ten, twenty-five, and fifty grams was well tolerated by the participants. The administration of erythritol induced a statistically significant dose-dependent stimulation of gut hormones such as plasma cholecystokinin, active glucagon‐like peptide‐1 and peptide tyrosine. Compared to the placebo, participants had slower gastric emptying with erythritol. Erythritol had no effect on the levels of motilin, glucose-dependent insulinotropic polypeptide, blood glucose, insulin, glucagon, blood lipids, or uric acid. Erythritol should be evaluated in larger, robust studies to determine whether it improves glycaemic control. However, healthcare professionals can use the results of this study to understand the potential uses of erythritol in the management of obesity and type 2 diabetes.
Abstract
AIM: To determine whether a dose-dependent effect in the stimulation of gut hormone release (plasma cholecystokinin [CCK], active glucagon-like peptide-1 [aGLP-1] and peptide tyrosine tyrosine [PYY]) is found for the natural sweetener erythritol. MATERIALS AND METHODS Twelve healthy, lean volunteers received solutions with 10, 25 or 50 g erythritol, or tap water enriched with 13 C-sodium acetate on four study days via a nasogastric tube in this randomized (active treatments), placebo-controlled, double-blind, cross-over trial. Blood samples and breath samples (13 C-sodium acetate method for measurement of gastric emptying [GE]) were taken at regular intervals, and sensations of appetite and gastrointestinal symptoms were rated. RESULTS We found (a) a dose-dependent stimulation of CCK, aGLP-1 and PYY, and slowing of GE, (b) no effect on blood glucose, insulin, motilin, glucagon or glucose-dependent insulinotropic polypeptide, (c) no effect on blood lipids and uric acid, and (d) no abdominal pain, nausea or vomiting. CONCLUSIONS Solutions with 10 and 50 g of erythritol stimulated gut hormone release. Emptying of erythritol-containing solutions from the stomach was slower compared with placebo. There was no effect on plasma glucose, insulin, glucagon, blood lipids or uric acid. All doses were well tolerated.
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Nicotinamide riboside supplementation alters body composition and skeletal muscle acetylcarnitine concentrations in healthy obese humans.
Remie, CME, Roumans, KHM, Moonen, MPB, Connell, NJ, Havekes, B, Mevenkamp, J, Lindeboom, L, de Wit, VHW, van de Weijer, T, Aarts, SABM, et al
The American journal of clinical nutrition. 2020;112(2):413-426
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Nicotinamide riboside (NR) is a member of the vitamin B3 family, which is naturally found in the diet and may improve metabolic functions. Improved metabolism can improve several diseases such as type 2 diabetes and obesity. This 6-week randomised control trial of 13 overweight and obese men and women aimed to investigate the effect of NR supplementation on metabolism. The results showed that supplementation improved muscle metabolism and body fat percentage, although total body weight remained unchanged. Supplementation did not improve markers for pre-diabetes or heart function. It was concluded that NR supplementation may improve muscle metabolism, however no other health effects were observed. This study could be used by healthcare professionals to understand that supplementation with NR may improve muscle function in overweight and obese individuals.
Abstract
BACKGROUND Nicotinamide riboside (NR) is an NAD+ precursor that boosts cellular NAD+ concentrations. Preclinical studies have shown profound metabolic health effects after NR supplementation. OBJECTIVES We aimed to investigate the effects of 6 wk NR supplementation on insulin sensitivity, mitochondrial function, and other metabolic health parameters in overweight and obese volunteers. METHODS A randomized, double-blinded, placebo-controlled, crossover intervention study was conducted in 13 healthy overweight or obese men and women. Participants received 6 wk NR (1000 mg/d) and placebo supplementation, followed by broad metabolic phenotyping, including hyperinsulinemic-euglycemic clamps, magnetic resonance spectroscopy, muscle biopsies, and assessment of ex vivo mitochondrial function and in vivo energy metabolism. RESULTS Markers of increased NAD+ synthesis-nicotinic acid adenine dinucleotide and methyl nicotinamide-were elevated in skeletal muscle after NR compared with placebo. NR increased body fat-free mass (62.65% ± 2.49% compared with 61.32% ± 2.58% in NR and placebo, respectively; change: 1.34% ± 0.50%, P = 0.02) and increased sleeping metabolic rate. Interestingly, acetylcarnitine concentrations in skeletal muscle were increased upon NR (4558 ± 749 compared with 3025 ± 316 pmol/mg dry weight in NR and placebo, respectively; change: 1533 ± 683 pmol/mg dry weight, P = 0.04) and the capacity to form acetylcarnitine upon exercise was higher in NR than in placebo (2.99 ± 0.30 compared with 2.40 ± 0.33 mmol/kg wet weight; change: 0.53 ± 0.21 mmol/kg wet weight, P = 0.01). However, no effects of NR were found on insulin sensitivity, mitochondrial function, hepatic and intramyocellular lipid accumulation, cardiac energy status, cardiac ejection fraction, ambulatory blood pressure, plasma markers of inflammation, or energy metabolism. CONCLUSIONS NR supplementation of 1000 mg/d for 6 wk in healthy overweight or obese men and women increased skeletal muscle NAD+ metabolites, affected skeletal muscle acetylcarnitine metabolism, and induced minor changes in body composition and sleeping metabolic rate. However, no other metabolic health effects were observed.This trial was registered at clinicaltrials.gov as NCT02835664.
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Impact of Experimentally Induced Cognitive Dietary Restraint on Eating Behavior Traits, Appetite Sensations, and Markers of Stress during Energy Restriction in Overweight/Obese Women.
Morin, I, Bégin, C, Maltais-Giguère, J, Bédard, A, Tchernof, A, Lemieux, S
Journal of obesity. 2018;2018:4259389
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The treatment of obesity has become a public health priority given the negative impact of this condition on physical and mental health. The aim of this study was to compare the effects of energy restriction alone or in combination with induced cognitive dietary restraint (CDR) on eating behaviour traits, appetite sensations, and markers of stress in overweight and obese premenopausal women. The study is a single-blinded randomised clinical study which recruited premenopausal women aged between 26 and 50 years. The participants were randomised to either an energy-restriction-plus-induced CDR condition (CDR+group) or an energy-restriction-without induced CDR condition (CDR−group). Results indicate that inducing CDR in a context of energy restriction had no further effects on eating behaviour traits, appetite sensations, and markers of stress in the short term as well as in the longer term than energy restriction alone. Authors conclude that increasing CDR has no negative impact on factors regulating energy balance in the context of energy restriction.
Abstract
Weight loss has been associated with changes in eating behaviors and appetite sensations that favor a regain in body weight. Since traditional weight loss approaches emphasize the importance of increasing cognitive dietary restraint (CDR) to achieve negative energy imbalance, it is difficult to untangle the respective contributions of energy restriction and increases in CDR on factors that can eventually lead to body weight regain. The present study aimed at comparing the effects of energy restriction alone or in combination with experimentally induced CDR on eating behavior traits, appetite sensations, and markers of stress in overweight and obese women. We hypothesized that the combination of energy restriction and induced CDR would lead to more prevalent food cravings, increased appetite sensations, and higher cortisol concentrations than when energy restriction is not coupled with induced CDR. A total of 60 premenopausal women (mean BMI: 32.0 kg/m2; mean age: 39.4 y) were provided with a low energy density diet corresponding to 85% of their energy needs during a 4-week fully controlled period. At the same time, women were randomized to either a condition inducing an increase in CDR (CDR+ group) or a condition in which CDR was not induced (CRD- group). Eating behavior traits (Three-Factor Eating Questionnaire and Food Craving Questionnaire), appetite sensations (after standardized breakfast), and markers of stress (Perceived Stress Scale; postawakening salivary cortisol) were measured before (T = 0 week) and after (T = 4 weeks) the 4-week energy restriction, as well as 3 months later. There was an increase in CDR in the CDR+ group while no such change was observed in the CDR- group (p=0.0037). No between-group differences were observed for disinhibition, hunger, cravings, appetite sensations, perceived stress, and cortisol concentrations. These results suggest that a slight increase in CDR has no negative impact on factors regulating energy balance in the context of energy restriction.
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Effect of the artificial sweetener, sucralose, on gastric emptying and incretin hormone release in healthy subjects.
Ma, J, Bellon, M, Wishart, JM, Young, R, Blackshaw, LA, Jones, KL, Horowitz, M, Rayner, CK
American journal of physiology. Gastrointestinal and liver physiology. 2009;296(4):G735-9
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Artificial sweeteners have been used to replace carbohydrate in the management of diabetes and obesity. Sucralose is a noncaloric sweetener derived from sucrose and is ∼600 times sweeter. The aims of this study were to evaluate the incretin [metabolic hormone], insulin, and glycaemic responses to sucralose administration and to determine whether this artificial sweetener is capable of generating feedback in the small intestine that slows gastric emptying in healthy humans. This study studied seven healthy subjects whose average age was 24 years. Each subject attended the Discipline of Medicine at the Royal Adelaide Hospital on four occasions (after 14hr overnight fast), each separated by 3–7 days. Women were studied in the follicular phase of the menstrual cycle. Results indicate that fasting blood glucose concentrations and plasma incretin and insulin concentrations did not differ between the four study days. Authors conclude that artificial sweeteners may have no therapeutic benefit in the dietary management of diabetes, other than as a substitute for carbohydrate.
Abstract
The incretin hormones, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), play an important role in glucose homeostasis in both health and diabetes. In mice, sucralose, an artificial sweetener, stimulates GLP-1 release via sweet taste receptors on enteroendocrine cells. We studied blood glucose, plasma levels of insulin, GLP-1, and GIP, and gastric emptying (by a breath test) in 7 healthy humans after intragastric infusions of 1) 50 g sucrose in water to a total volume of 500 ml (approximately 290 mosmol/l), 2) 80 mg sucralose in 500 ml normal saline (approximately 300 mosmol/l, 0.4 mM sucralose), 3) 800 mg sucralose in 500 ml normal saline (approximately 300 mosmol/l, 4 mM sucralose), and 4) 500 ml normal saline (approximately 300 mosmol/l), all labeled with 150 mg 13C-acetate. Blood glucose increased only in response to sucrose (P<0.05). GLP-1, GIP, and insulin also increased after sucrose (P=0.0001) but not after either load of sucralose or saline. Gastric emptying of sucrose was slower than that of saline (t50: 87.4+/-4.1 min vs. 74.7+/-3.2 min, P<0.005), whereas there were no differences in t50 between sucralose 0.4 mM (73.7+/-3.1 min) or 4 mM (76.7+/-3.1 min) and saline. We conclude that sucralose, delivered by intragastric infusion, does not stimulate insulin, GLP-1, or GIP release or slow gastric emptying in healthy humans.