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Blueberries Improve Abdominal Symptoms, Well-Being and Functioning in Patients with Functional Gastrointestinal Disorders.
Wilder-Smith, CH, Materna, A, Olesen, SS
Nutrients. 2023;15(10)
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Functional gastrointestinal disorders (FGID) are the most common cause of recurring, chronic digestive upsets. Irritable bowel syndrome (IBS) and functional dyspepsia (FD), or persistent indigestion, are the most prevalent types of those disorders. Typical symptoms include pain or discomfort in the abdomen, changes in stool patterns or bloating and may also manifest in symptoms not directly relating to the digestive tract. It remains uncertain what the exact mechanisms of those disorders are. However, scientists identified various factors involved, including immune system activation, sensitisation of the nervous system, dysregulated permeability of the gut walls, and changes in the microbiota, their composition and metabolic activity. Polyphenols are natural compounds found abundantly in plants and are most known for their antioxidant qualities. One frequently studied and rich-source of phenols is Blueberries (Vaccinium spp). Blueberries have antioxidant, anti-inflammatory, and neuroprotective properties, and are known to reverse the permeability of the gut membrane. Hence their use in the management of FGID appeared promising. This double-blind, randomized, cross-over study assessed the benefit of blueberries in 43 people with IBS or FD, between 18–60 years of age. The candidates were given 30g freeze-dried blueberries, the equivalent of 180g of fresh blueberries, or a sugar-based placebo of similar calorific value for 6-weeks each. When receiving the blueberries, greater symptom relief was observed when compared to the placebo group. Blueberry intake also positively reflected in experienced improvement in quality of life. No notable differences were observed between groups in stool patterns and fructose digestion. Blueberries and their beneficial compounds such as polyphenols and fiber appear to have a wide range of benefits that can help manage some of the FGID-associated symptoms. Further studies are needed to understand why, despite some notable benefits, some of the other GI markers remained unaffected. As blueberries are generally well tolerated, they can be a simple and helpful food intervention to complement other FGID management strategies.
Abstract
Blueberries beneficially modulate physiologic mechanisms relevant to the pathogenesis of functional gastrointestinal disorders (FGID). Forty-three patients with FGID received freeze-dried blueberries (equivalent to 180 g fresh blueberries) or sugar and energy-matched placebo in a double-blind, randomized, cross-over study. After 6 weeks of treatment, the differences in Gastrointestinal Clinical Rating Scale (GSRS) scores and abdominal symptom relief were compared as primary outcome measures. The quality of life and life functioning ratings (OQ45.2 questionnaire), Bristol stool scales, and fructose breath test results constituted secondary outcome measures. Blueberry treatment resulted in more patients with relevant abdominal symptom relief compared to placebo (53% vs. 30%, p = 0.03). Total and pain GSRS scores improved insignificantly (mean treatment differences [95% CI]: -3.4 [-7.4 to 0.6] (p = 0.09) and -1.0 [-2.2 to 0.1] (p = 0.08), respectively). OQ45.2 scores improved during blueberry treatment compared to placebo (treatment difference -3.2 [95% CI: -5.6 to -0], p = 0.01). Treatment effect differences for the further measures did not reach statistical significance. Blueberries relieved abdominal symptoms and improved general markers of well-being, quality of life, and life functioning more than placebo in patients with FGID. Consequently, the polyphenol and fiber components of blueberries exert broad beneficial effects separate from the sugars present in both treatments.
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Restricting sugar or carbohydrate intake does not impact physical activity level or energy intake over 24 h despite changes in substrate use: a randomised crossover study in healthy men and women.
Hengist, A, Davies, RG, Rogers, PJ, Brunstrom, JM, van Loon, LJC, Walhin, JP, Thompson, D, Koumanov, F, Betts, JA, Gonzalez, JT
European journal of nutrition. 2023;62(2):921-940
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Diets high in carbohydrates especially when consumed in sugar-sweetened food and beverages has been shown to result in increased energy intakes in the diet. However, diets low in sugar and carbohydrates have been shown to have a limited effect on changes in body mass and weight loss. In this instance, some other mechanism is preventing weight loss. Diets low in carbohydrates have been shown to decrease physical activity levels and energy expenditure, which may be responsible for the limited weight loss seen with carbohydrate restricted diets. This randomised control trial of 25 individuals aimed to determine whether carbohydrate restriction would reduce physical activity energy expenditure over a 24-hour period compared to diets higher in sugar and/or carbohydrates. Individuals with a low dietary intake of sugar and carbohydrates and moderate intake of sugar all showed similar physical activity energy expenditure levels. Interestingly low carbohydrate intake resulted in the highest 24 hour increase in low density lipoprotein concentrations and decreased satiety hormones. It was concluded that when energy density is controlled, restricting sugar or carbohydrates has no effect on physical activity levels over a 24-hour period. This study could be used by healthcare professionals that in the very short-term low sugar and carbohydrate diets have no effect on physical activity levels but does affect metabolic changes. However studies need to be performed to determine long-term effects.
Abstract
PURPOSE To determine the effects of dietary sugar or carbohydrate restriction on physical activity energy expenditure, energy intake, and physiological outcomes across 24 h. METHODS In a randomized, open-label crossover design, twenty-five healthy men (n = 10) and women (n = 15) consumed three diets over a 24-h period: moderate carbohydrate and sugar content (MODSUG = 50% carbohydrate [20% sugars], 15% protein, 35% fat); low sugar content (LOWSUG = 50% carbohydrate [< 5% sugars], 15% protein, 35% fat); and low carbohydrate content (LOWCHO = 8% carbohydrate [< 5% sugars], 15% protein, 77% fat). Postprandial metabolic responses to a prescribed breakfast (20% EI) were monitored under laboratory conditions before an ad libitum test lunch, with subsequent diet and physical activity monitoring under free-living conditions until blood sample collection the following morning. RESULTS The MODSUG, LOWSUG and LOWCHO diets resulted in similar mean [95%CI] rates of both physical activity energy expenditure (771 [624, 919] vs. 677 [565, 789] vs. 802 [614, 991] kcal·d-1; p = 0.29] and energy intake (2071 [1794, 2347] vs. 2195 [1918, 2473] vs. 2194 [1890, 2498] kcal·d-1; P = 0.34), respectively. The LOWCHO condition elicited the lowest glycaemic and insulinaemic responses to breakfast (P < 0.01) but the highest 24-h increase in LDL-cholesterol concentrations (P < 0.001), with no differences between the MODSUG and LOWSUG treatments. Leptin concentrations decreased over 24-h of consuming LOWCHO relative to LOWSUG (p < 0.01). CONCLUSION When energy density is controlled for, restricting either sugar or total dietary carbohydrate does not modulate physical activity level or energy intake over a 24-h period (~ 19-h free-living) despite substantial metabolic changes. CLINICAL TRIALS REGISTRATION ID NCT03509610, https://clinicaltrials.gov/show/NCT03509610.
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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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Host-diet-gut microbiome interactions influence human energy balance: a randomized clinical trial.
Corbin, KD, Carnero, EA, Dirks, B, Igudesman, D, Yi, F, Marcus, A, Davis, TL, Pratley, RE, Rittmann, BE, Krajmalnik-Brown, R, et al
Nature communications. 2023;14(1):3161
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Composition of the human gut microbiome has been shown to be associated with chronic diseases such as obesity, however whether they have a causal effect in disease development or whether microbiota composition is a direct result of the disease is unclear. This randomised control trial of 17 individuals aimed to determine the effects of a diet designed to modulate the gut microbiome (MBD) on human energy balance compared to a typical Western style diet (WD). The MBD diet maximised fibre, resistant starch, and limited processed foods and resulted in a significant decrease in the amount of energy produced by individuals compared to the WD. It was also shown that the MBD increased the microbial composition and decreased nutrient breakdown. It was concluded that the MBD increased the amount of gut bacteria and altered the amount of energy produced by individuals on this diet. This study could be used by healthcare practitioners to understand that composition of the gut microbiome can affect the amount of energy gained from food. Diets high in fibre, starch and low in processed foods, which promote microbial diversity may help individuals to lose weight.
Abstract
The gut microbiome is emerging as a key modulator of human energy balance. Prior studies in humans lacked the environmental and dietary controls and precision required to quantitatively evaluate the contributions of the gut microbiome. Using a Microbiome Enhancer Diet (MBD) designed to deliver more dietary substrates to the colon and therefore modulate the gut microbiome, we quantified microbial and host contributions to human energy balance in a controlled feeding study with a randomized crossover design in young, healthy, weight stable males and females (NCT02939703). In a metabolic ward where the environment was strictly controlled, we measured energy intake, energy expenditure, and energy output (fecal and urinary). The primary endpoint was the within-participant difference in host metabolizable energy between experimental conditions [Control, Western Diet (WD) vs. MBD]. The secondary endpoints were enteroendocrine hormones, hunger/satiety, and food intake. Here we show that, compared to the WD, the MBD leads to an additional 116 ± 56 kcals (P < 0.0001) lost in feces daily and thus, lower metabolizable energy for the host (89.5 ± 0.73%; range 84.2-96.1% on the MBD vs. 95.4 ± 0.21%; range 94.1-97.0% on the WD; P < 0.0001) without changes in energy expenditure, hunger/satiety or food intake (P > 0.05). Microbial 16S rRNA gene copy number (a surrogate of biomass) increases (P < 0.0001), beta-diversity changes (whole genome shotgun sequencing; P = 0.02), and fermentation products increase (P < 0.01) on an MBD as compared to a WD along with significant changes in the host enteroendocrine system (P < 0.0001). The substantial interindividual variability in metabolizable energy on the MBD is explained in part by fecal SCFAs and biomass. Our results reveal the complex host-diet-microbiome interplay that modulates energy balance.
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An insight into the functional alterations in the gut microbiome of healthy adults in response to a multi-strain probiotic intake: a single arm open label trial.
Rodenes-Gavidia, A, Lamelas, A, Bloor, S, Hobson, A, Treadway, S, Haworth, J, Vijayakumar, V, Naghibi, M, Day, R, Chenoll, E
Frontiers in cellular and infection microbiology. 2023;13:1240267
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The human gut microbiota is a key mediator of host health and is known to affect many physiological processes, such as digestion, metabolism, immune function and inhibition of pathogen colonisation. The gut microbiome can be impacted by many extrinsic factors. The aim of this study was to assess both compositional and functional changes in the microbiome of healthy individuals using shotgun metagenomics following 8-weeks of daily multi-strain probiotic intake. This study was a single-arm open-label study which enrolled a total of 41 healthy adult males and females between 18 to 40 years old. Results showed that alpha- and beta-diversity of the faecal microbiota structure was not significantly altered in response to probiotic intake. However, significant changes were observed when functional genes were assessed. Abundance of certain genes involved in several functional pathways were also significantly altered. Additionally, there were no significant changes in stool frequency or consistency, faecal biochemistry, or breath tests of methane and hydrogen observed. Authors conclude that the findings of their study have the potential to provide insights into the underlying mechanisms of action of the 14-strain probiotic blend in healthy adults.
Abstract
BACKGROUND Probiotic supplements, by definition, provide a benefit to the host, but few studies have investigated the effect of probiotic supplements in healthy adult populations. PURPOSE The present, single arm, open label clinical trial, evaluated compositional and functional changes in the fecal microbiome of healthy adults after supplementation with a 14-strain probiotic. METHODS We analysed the effect of a 14-strain probiotic blend (Bacillus subtilis NCIMB 30223, Bifidobacterium bifidum NCIMB 30179, B. breve NCIMB 30180, B. infantis NCIMB 30181, B. longum NCIMB 30182, Lactobacillus helveticus NCIMB 30184, L. delbrueckii subsp. bulgaricus NCIMB 30186, Lacticaseibacillus paracasei NCIMB 30185, Lactiplantibacillus plantarum NCIMB 30187, Lacticaseibacillus rhamnosus NCIMB 30188, L. helveticus NCIMB 30224, Lactobacillus salivarius NCIMB 30225, Lactococcus lactis subsp. lactis NCIMB 30222, and Streptococcus thermophilus NCIMB 30189), on the faecal microbiota of healthy young adults (n=41) in a single arm study. The adults consumed 4 capsules daily of the 14 strain blend(8 billion colony forming units/day) for 8 weeks. Compositional and functional changes in faecal microbiota before and after supplementation were assessed using shotgun metagenomic sequencing. Fasting breath analysis, faecal biochemistry and bowel habits were also assessed. RESULTS In healthy adult participants, no significant changes to the overall alpha- or beta-diversity was observed after 8 weeks of multi-strain probiotic supplementation. However, in a simplified model that considered only time and individual differences, significant decreases (p < 0.05) in family Odoribacteraceae and Bacteroidaceae abundance and a significant increase (p < 0.05) in genus Megamonas abundance were observed. At a functional level, there were significant changes in functional gene abundance related to several functional pathways, including phenylalanine metabolism, O-antigen nucleotide sugar biosynthesis, bacterial chemotaxis, and flagellar assembly. No significant changes in stool form or frequency, fecal biochemistry, or methane and hydrogen breath tests were observed. CONCLUSION In healthy young adults, overall alpha- and beta-diversity did not change in response to probiotic intake even though modest compositional changes at the family and genus level were observed. However, at functional level, results identified changes in gene abundance for several functional pathways.
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Efficacy of incremental loads of cow's milk as a treatment for lactose malabsorption in Japan.
Hasegawa, M, Okada, K, Nagata, S, Sugihara, S
World journal of clinical cases. 2023;11(4):797-808
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Lactose intolerance (LI) is a reduced ability to digest the sugar lactose, which is found in milk and products containing milk. Symptoms include gastrointestinal disturbances. Current treatments include the digestion of large volumes of lactose daily to adapt the colon to tolerate digestion, however this treatment is considered too extreme for Japanese LI sufferers. This clinical trial aimed to determine the effectiveness of performing lactose tolerance acquisition treatment in 46 Japanese individuals with LI. The results showed that lactose malabsorption is responsible for most LI cases. Lactose loading improved the symptoms and severity of LI in 29 of the individuals, but 16 showed no changes in symptoms or severity of disease. It was concluded that in most individuals from Japan with LI, incremental lactose loading with cow’s milk may be a useful treatment. This study could be used by healthcare professionals to understand that if properly managed, lactose loading may be an effective therapy for LI for individuals who may be particularly sensitive to lactose due to heritage.
Abstract
BACKGROUND Lactose intolerance (LI) is commonly seen in East Asian countries. Several studies showed that lactose or milk loading has been used as a treatment for lactose malabsorption (LM) in Western countries, but there have been no reports regarding this type of treatment in Japan. As lactose or milk loading requires ingestion of large amounts of lactose within a short period, this is considered to be too harsh for Japanese people because of their less habitual milk consumption (175 mL per day in average) than Western people. In this study, we demonstrated lactose tolerance acquisition in a suitable way for Japanese. AIM: To examine the efficacy of lactose (cow's milk) loading treatment in patients with LM. METHODS Individuals with abdominal symptoms induced by milk or dairy products (LI symptoms) were identified with a questionnaire. A 20 g lactose hydrogen breath test (LHBT) was carried out to confirm LM diagnosis and to evaluate co-existence of small intestinal bacterial overgrowth (SIBO). Respondents diagnosed with LM were selected as study subjects and were treated with incremental loads of cow's milk, starting from 30 mL and increasing up to 200 mL at 4-7 d intervals. After the treatment, changes in symptoms and LM diagnostic value of 20 g LHBT were investigated. Stool samples pre- and post-treatment were examined for changes in intestinal microbiota using 16S rRNA sequencing. Informed consent was obtained prior to each stage of the study. RESULTS In 46 subjects with LI symptoms (10-68 years old, mean age 34 years old) identified with the questionnaire, 35 (76.1%) were diagnosed with LM by 20 g LHBT, and 6 had co-existing SIBO. The treatment with incremental cow's milk was carried out in 32 subjects diagnosed with LM (14-68 years old, median age 38.5 years old). The mean period of the treatment was 41 ± 8.6 d. Improvement of symptoms was observed in 29 (90.6%; 95% confidence interval: 75.0%-98.0 %) subjects. Although 20 g LHBT indicated that 10 (34.5%) subjects had improved diagnostic value of LM, no change was observed in 16 (55.2%) subjects. Analysis of the fecal intestinal microbiota showed a significant increase in Blautia in 7 subjects who became symptom-free after the treatment (P = 0.0313). CONCLUSION LM was diagnosed in approximately 75% of the subjects who had LI. Incremental loads of cow's milk is regarded as a useful treatment for LM without affecting everyday life.
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Effect of Docosahexaenoic Acid and Eicosapentaenoic Acid Supplementation on Sleep Quality in Healthy Subjects: A Randomized, Double-Blinded, Placebo-Controlled Trial.
Yokoi-Shimizu, K, Yanagimoto, K, Hayamizu, K
Nutrients. 2022;14(19)
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Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are unsaturated Omega-3 fatty acids, primarily found in fish and seafood. The fatty acids fulfil many vital roles in the body, such as creating cell membranes, supporting brain functions and being associated with many disease-protective benefits. These fatty acids also influence sleep in children and young adults, but less is known about their effect in older people. Hence, this Japanese study investigated the impact of EPA and DHA on sleep quality in people above the age of ≥ 45. 66 males and females with poor sleep participated in this randomized, placebo-controlled, double-blinded, parallel-grouped study. They either received 860 mg of combined DHA/EPA per day (576 mg DHA/284 mg EPA) or a placebo of corn oil for 12 weeks. The outcome was assessed subjectively via sleep quality and mood questionnaires, as well as objectively with a sleep scanner and blood samples. Blood samples and blood pressure where also monitored as a safety measure. Upon completion of the study there was a subjective improvement, which was backed-up by the results of the sleep scanner. This study confirmed that DHA/EPA improves sleep quality in the middle aged and older population and does so at doses lower than those administered in previous studies. The authors had set the daily minimum intake of DHA/EPA at 860 mg/day for this trial, as previous research showed no effects at lower doses. They also noted that poor responders tended to be people with pre-existing conditions or those who were pregnant. This population may require higher dosages of DHA/EPA than healthy patients. Overall, the intervention was well tolerated. Ensuring adequate DHA and EPA levels and intake could be part of nutritional strategies for sleep support.
Abstract
Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)-omega-3 fatty acids with various functions-influence sleep in children and young adults. However, only limited studies on their effects on sleep in middle- and old-aged adults have been reported. Therefore, we investigated the effects of DHA and EPA on sleep quality in subjects aged ≥ 45 years. We performed a randomized, placebo-controlled, double-blinded, parallel-grouped study, in which we randomly assigned 66 healthy Japanese males and females. Each individual received six 480 mg capsules containing 576 mg DHA and 284 mg EPA per day (DHA/EPA group, n = 33), or corn oil (placebo group, n = 33), for 12 weeks. Before and after the intervention, the Oguri-Shirakawa-Azumi sleep inventory MA version (OSA-MA) and the sleep state test were conducted. In the DHA/EPA group, factor III (frequent dreaming) scores among the OSA-MA scores were significantly improved compared to the placebo group. Additionally, sleep state tests revealed that sleep efficiency improved in the DHA/EPA group. To our knowledge, this study is the first to report that DHA/EPA improves sleep quality in middle- and old-aged individuals, even at doses lower than those administered in previous studies.
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Effects of Low-Carbohydrate versus Mediterranean Diets on Weight Loss, Glucose Metabolism, Insulin Kinetics and β-Cell Function in Morbidly Obese Individuals.
Tricò, D, Moriconi, D, Berta, R, Baldi, S, Quinones-Galvan, A, Guiducci, L, Taddei, S, Mari, A, Nannipieri, M
Nutrients. 2021;13(4)
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Both low-carbohydrate and Mediterranean style diets are used to prevent lifestyle associated diseases such as obesity and type 2 diabetes. However, which diet is more effective is unclear. The aim of this randomised control trial of 36 morbidly obese individuals was to compare the effectiveness of Mediterranean diets and low-carbohydrate diets to improve metabolic measures such as blood sugar levels, pre-diabetes, and the body’s ability to use sugar. The results showed that in the short-term both diets were equally effective at improving biochemical dysfunctions that contribute to type 2 diabetes. The low-carbohydrate diet did result in higher weight loss than the Mediterranean diet. Studies on long-term effects are warranted. It was concluded that a low-carbohydrate diet is in the short-term a feasible alternative to the Mediterranean diet for improved weight loss and biological contributors to type 2 diabetes. This study could be used by healthcare professionals to understand that the Mediterranean diet and low-carbohydrate diet are both effective in the short-term for improvements to contributors to type 2 diabetes, however the low-carbohydrate diet may be superior if weight loss is required.
Abstract
Low-calorie Mediterranean-style or low-carbohydrate dietary regimens are widely used nutritional strategies against obesity and associated metabolic diseases, including type 2 diabetes. The aim of this study was to compare the effectiveness of a balanced Mediterranean diet with a low-carbohydrate diet on weight loss and glucose homeostasis in morbidly obese individuals at high risk to develop diabetes. Insulin secretion, insulin clearance, and different β-cell function components were estimated by modeling plasma glucose, insulin and C-peptide profiles during 75-g oral glucose tolerance tests (OGTTs) performed at baseline and after 4 weeks of each dietary intervention. The average weight loss was 5%, being 58% greater in the low-carbohydrate-group than Mediterranean-group. Fasting plasma glucose and glucose tolerance were not affected by the diets. The two dietary regimens proved similarly effective in improving insulin resistance and fasting hyperinsulinemia, while enhancing endogenous insulin clearance and β-cell glucose sensitivity. In summary, we demonstrated that a low-carbohydrate diet is a successful short-term approach for weight loss in morbidly obese patients and a feasible alternative to the Mediterranean diet for its glucometabolic benefits, including improvements in insulin resistance, insulin clearance and β-cell function. Further studies are needed to compare the long-term efficacy and safety of the two diets.
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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.