1.
Comparative effects of vitamin and mineral supplements in the management of type 2 diabetes in primary care: A systematic review and network meta-analysis of randomized controlled trials.
Xia, J, Yu, J, Xu, H, Zhou, Y, Li, H, Yin, S, Xu, D, Wang, Y, Xia, H, Liao, W, et al
Pharmacological research. 2023;188:106647
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Type 2 diabetes mellitus (T2DM), characterised by sustained hyperglycaemia and insulin resistance, remains a severe driver of chronic metabolic diseases such as cardiovascular diseases. The aim of this study was to investigate and compare the efficacy of vitamin and mineral supplements in the management of glycaemic control and lipid metabolism for type 2 diabetic patients to inform clinical practice. This study is a systematic review and meta-analysis of one hundred and seventy articles with a total of 4223 adults with T2DM. Participants were randomised to either the placebo/no treatment group (n= 6345) or to the treatment group (n= 7878). Results show that: - chromium was the most effective micronutrient for decreasing fasting blood glucose and insulin resistance. - vitamin K was the top-ranked micronutrient in reducing haemoglobin A1C and fasting insulin levels. - vanadium was the top-ranked micronutrient in total cholesterol reductions. - niacin was ranked as the most effective in triglycerides reductions and increasing high-density lipoprotein cholesterol levels. - vitamin E was the top-ranked micronutrient in low-density lipoprotein cholesterol reductions. Authors conclude that micronutrient supplements especially chromium, vitamin E, vitamin K, vanadium, and niacin supplements, may be more effective in the management of T2DM compared with other micronutrients.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Clinicians could consider the adjunctive effect of micronutrients supplements, such as chromium, vitamin E, vitamin K, vanadium, and niacin supplements in a nutrition protocol to manage T2DM and slow or prevent its complications.
- The study authors state that the vitamin and mineral supplements under review had a statistically significant improvement, however they did not reach the study threshold for clinical significance. Therefore they advise caution in utilising micronutrient supplements in the management of glucose and lipid metabolism for T2DM.
Evidence Category:
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X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Objectives
The aim of this systematic review was to evaluate the comparative effects of vitamin and mineral supplements on managing glycemic control and lipid metabolism for type 2 diabetes mellitus (T2DM).
Methodology
This systematic review is registered with PROSPERO and adhered to PRISMA-2020 guidelines for network meta-analysis
The Cochrane Collaboration’s risk-of-bias tool was used to assess eligible randomised trials
8 prespecified markers identified and assessed in this study : 1) HbA1c (%), 2) fasting blood glucose (mmol/L), 3) total cholesterol (mmol/L), 4) triglycerides (mmol/L), 5) fasting insulin (μIU/mL), 6) HOMA-IR, 7) LDL-c (mmol/L), and 8) HDL-c (mmol/L).
Results
- 170 RCT trials of 14223 participants with T2DM treated with vitamin supplements, mineral supplements, or placebo/no treatment were included
- Low to very low certainty evidence established chromium supplements as the most effective in reducing fasting blood glucose levels and homeostasis model assessment of insulin resistance (SUCRAs: 90.4% and 78.3%, respectively)
- Vitamin K supplements ranked best in reducing glycated haemoglobin A1c and fasting insulin levels (SUCRAs: 97.0% and 82.3%, respectively), with moderate to very low certainty evidence
- Vanadium supplements ranked best in lowering total cholesterol levels with very low evidence certainty (SUCRAs:100%)
- Niacin supplements ranked best in triglyceride reductions and increasing high-density lipo-protein cholesterol levels with low to very low evidence certainty (SUCRAs:93.7% and 94.6%, respectively)
- Vitamin E supplements ranked best in reducing low-density lipoprotein cholesterol levels with very low evidence certainty (SUCRAs:80.0%).
Conclusion
- Micronutrient supplements, such as chromium, vitamin E, vitamin K, vanadium, and niacin supplements, may be efficacious in managing T2DM
- It should be noted that the evidence certainty for all was low.
Clinical practice applications:
- Chromium plays an important role in carbohydrate and lipid metabolism and was the most effective micronutrient for decreasing fasting blood glucose, HbA1c, fasting insulin, and HOMA-IR reductions. More pronounced effects were seen for chromium than vitamin E, vitamin C, niacin, selenium, and magnesium supplements
- Vitamin K was the top-ranked micronutrient in reducing HbA1c and fasting insulin levels. The mechanism through which Vitamin K affects glucose metabolism is proposed as activation of the AMP-activated protein kinase/sirtuin 1, that in turn increases phosphocreatine 3-kinase and glucose transporter 2 to decrease insulin resistance and fasting glucose.
- Vanadium was the top-ranked micronutrient in total cholesterol (TC) reductions, where supplementation dosage should be carefully considered, as vanadium compounds can be moderately or highly toxic. Vanadium supplementation is only recommended in cases of vanadium deficiency or diabetes, hyperlipidemia, and hypertension, where the intake of vanadium from food should be enhanced in preference to supplementation
- Niacin was ranked as the most effective in triglyceride (TG) reductions and increasing HDL cholesterol levels. The dose of niacin could not be determined
- Vitamin E was the top-ranked micronutrient in low-density lipo- protein (LDL) cholesterol reductions.
Considerations for future research:
- Considering the clinical importance of these findings, new research is needed to get better insight into the efficacy of micronutrient supplements in managing T2DM
- Selenium homeostasis, selenoprotein, insulin signaling/secretion, and carbohydrate/lipid metabolism are linked in multiple and complex ways but the authors could not explain why chromium supplementation would lower blood glucose more effectively than selenium supplementation, and suggest more research is needed to clarify this
- While vitamin K status could be an emerging treatment target in T2DM prevention and management, it remains to be determined whether vitamin K supplementation has an advantage over other nutrients in terms of hypoglycemic effect, and further research is necessary
- The beneficial effect of vitamin E and niacin supplements regarding lipid metabolism warrant investigation through more rigorous comparative studies.
Abstract
Medical nutrition treatment can manage diabetes and slow or prevent its complications. The comparative effects of micronutrient supplements, however, have not yet been well established. We aimed at evaluating the comparative effects of vitamin and mineral supplements on managing glycemic control and lipid metabolism for type 2 diabetes mellitus (T2DM) to inform clinical practice. Electronic and hand searches for randomized controlled trials (RCTs) were performed until June 1, 2022. We selected RCTs enrolling patients with T2DM who were treated with vitamin supplements, mineral supplements, or placebo/no treatment. Data were pooled via frequentist random-effects network meta-analyses. A total of 170 eligible trials and 14223 participants were included. Low to very low certainty evidence established chromium supplements as the most effective in reducing fasting blood glucose levels and homeostasis model assessment of insulin resistance (SUCRAs: 90.4% and 78.3%, respectively). Vitamin K supplements ranked best in reducing glycated hemoglobin A1c and fasting insulin levels (SUCRAs: 97.0% and 82.3%, respectively), with moderate to very low certainty evidence. Vanadium supplements ranked best in lowering total cholesterol levels with very low evidence certainty (SUCRAs:100%). Niacin supplements ranked best in triglyceride reductions and increasing high-density lipoprotein cholesterol levels with low to very low evidence certainty (SUCRAs:93.7% and 94.6%, respectively). Vitamin E supplements ranked best in reducing low-density lipoprotein cholesterol levels with very low evidence certainty (SUCRAs:80.0%). Our analyses indicated that micronutrient supplements, especially chromium, vitamin E, vitamin K, vanadium, and niacin supplements, may be more efficacious in managing T2DM than other micronutrients. Considering the clinical importance of these findings, new research is needed to get better insight into this issue.
2.
Nicotinamide adenine dinucleotide metabolism and arterial stiffness after long-term nicotinamide mononucleotide supplementation: a randomized, double-blind, placebo-controlled trial.
Katayoshi, T, Uehata, S, Nakashima, N, Nakajo, T, Kitajima, N, Kageyama, M, Tsuji-Naito, K
Scientific reports. 2023;13(1):2786
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Nicotinamide adenine dinucleotide (NAD+) is a coenzyme that plays a crucial role in energy metabolism and different biological processes. Sirtuins (SIRT1) are NAD+-dependent deacetylases, an enzyme that plays a key role in enhancing metabolic efficiency. Nicotinamide mononucleotide (NMN) is a precursor to NAD+. NMN supplementation may help to reduce the risk of developing metabolic diseases and cardiovascular diseases. This randomised, double-blinded, and placebo-controlled, parallel trial investigated the effects of 12 weeks of 125 mg NMN supplementation on metabolic health parameters, including CVD risk factors, blood NAD+ metabolites level, and SIRT1 expression in middle-aged men and women. Serum nicotinamide was significantly higher and arterial stiffness was lower in the NMN test group of middle-aged men and women after 12 weeks of NMN supplementation. The results of the study indicate that the administration of 250mg of nicotinamide mononucleotide (NMN) daily for an extended period is considered safe and well-tolerated. Healthcare professionals can use this finding to understand the significant implications of the use of NMN as a potential therapeutic agent in individuals seeking to improve their metabolic and cardiovascular health. Further robust studies are required to evaluate the effects of NMN supplementation due to the limitations and high baseline variability between the participants of this study.
Expert Review
Conflicts of interest:
None
Take Home Message:
- As we age, NAM levels decline, which could have a negative effect on cardiovascular health.
- Middle-aged adults may like to consider NMN supplementation to improve NAM metabolism and arterial stiffness.
- However, without data on CVD events, it is difficult to determine actual risk reductions.
Evidence Category:
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X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Introduction
- Nicotinamide adenine dinucleotide (NAD+) is a coenzyme involved in metabolism. When we age, NAD+ levels decline resulting in poorer metabolism and age-related disease such as cardiovascular disease (CVD). Nicotinamide mononucleotide (NMN) is a precursor in the biosynthesis of NAD+.
- This double-blind, randomised control trial aimed to determine the effect of supplementing NMN on NAD+ levels, CVD risk factors and sirtuin 1 (SIRT1) expression, which relies on NAD+ for adequate functioning.
Methods
- 36 healthy male and female individuals aged between 40-65 years of age were assigned to either NMN (125mg/day) or placebo for 12 weeks.
- One capsule was taken twice per day after meals.
- Serum nicotinamide (NAM), NAD+, NMN, advanced glycation end products (AGES), 8-hydroxydeoxyguanosine (8-OHdG) and SIRT1 mRNA expression were measured.
- The condition of blood vessels (arterial stiffness) was also assessed using the ankle brachial index (ABI).
- In a sub-analysis, individuals with hypertension, above average body mass index (BMI), or blood glucose level were also assessed for blood vessel condition using the ABI.
Results
- The results showed that from baseline serum NAM decreased in the placebo group (P=0.014), whereas it increased in the NMN group (P=0.006). This resulted in an increase in the NMN group compared to placebo (P=0.037).
- Interestingly serum NAM was lower in the NMN group compared to placebo at baseline (P=0.001).
- There was no statistically significant difference in ABI with NMN supplementation.
- Amongst those with hypertension there was also no change in ABI. However, those with high BMI or blood glucose, there was an improvement in vascular condition compared to placebo (P=<0.007 and P=0.019 respectively).
- 8-OHdG, SIRT1 mRNA and AGEs remained unchanged by NMN supplementation
Conclusion
- NMN supplementation enhanced NAD+ metabolism in middle-aged adults.
- It also relieved arterial stiffness and reduced CVD risk factors.
Clinical practice applications:
- Apparently healthy middle-aged adults who would like to activate NAD metabolism and decrease their risk for CVD, should consider 12-week supplementation with NMN (125mg/day).
- ABI should be monitored to ensure desired effects.
- It is unclear as to the effects of NMN supplementation after 12-weeks.
Considerations for future research:
- Future research should consider longer supplementation duration and/or adding in a follow-up period to determine duration of effect.
- Different supplemental doses should also be researched to determine an optimal dose.
Abstract
Many animal studies have shown that oral administration of the nicotinamide adenine dinucleotide (NAD+) precursor nicotinamide mononucleotide (NMN) prevents the reduction of NAD+ levels in organs and tissues, helping alleviate aging-related diseases. However, there are very few clinical reports of NMN supplementation in humans. Thus, this study aimed to investigate the influence of a 12-week NMN oral supplementation on biochemical and metabolic health parameters. A 12-week randomized, double-blind, placebo-controlled, parallel-group clinical trial was conducted. A total of 36 healthy middle-aged participants received one capsule of either 125 mg NMN or placebo twice a day. Among the NAD+ metabolites, the levels of nicotinamide in the serum were significantly higher in the NMN intake group than in the placebo group. Pulse wave velocity values indicating arterial stiffness tended to decrease in the NMN intake group. However, no significant difference was found between the two groups. Long-term NMN supplementation at 250 mg/day was well tolerated and did not cause adverse events. NMN safely and effectively elevated NAD+ metabolism in healthy middle-aged adults. Additionally, NMN supplementation showed potential in alleviating arterial stiffness.
3.
Effect of Intermittent Fasting Diet on Glucose and Lipid Metabolism and Insulin Resistance in Patients with Impaired Glucose and Lipid Metabolism: A Systematic Review and Meta-Analysis.
Yuan, X, Wang, J, Yang, S, Gao, M, Cao, L, Li, X, Hong, D, Tian, S, Sun, C
International journal of endocrinology. 2022;2022:6999907
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The prevalence of obesity and metabolic syndrome may increase the risk of cardiovascular disease (CVD), diabetes, and neurological conditions. The imbalance in glucose and lipid metabolism and hypertension characterises the development of these chronic diseases. Intermittent fasting (IF) has been considered an effective dietary strategy for reducing the risk of obesity, insulin resistance, dyslipidaemia, diabetes, and CVD. This systematic review and meta-analysis include ten randomised controlled trials to evaluate the effects of IF intervention on glucose and lipid metabolism in people with metabolic syndrome. IF intervention regulated glucose metabolism by improving fasting blood glucose, glycosylated haemoglobin, insulin, and insulin resistance. IF intervention also positively impacted the body mass index and waist circumference. The total cholesterol, low-density lipoprotein levels, and triglyceride levels also improved, followed by the IF, showing the impact on lipid metabolism. Further robust studies are required due to heterogeneity between the included studies in type of IF, duration, the health status of participants, ethnicity, and outcome measurements. However, healthcare professionals can use the results of this systematic review and meta-analysis to understand the therapeutic effect of IF intervention on glycolipid metabolism in people with metabolic syndrome.
Expert Review
Conflicts of interest:
None
Take Home Message:
- IF does not require calorie restriction which may result in greater compliance
- IF does not restrict macronutrients such as CHO and fats, so may avoid the exclusion of key nutrients e.g. healthy fats and wholegrains.
- IF may have fewer adverse effects on daily routines and quality of life, which may mean adherence is easier.
- Improved glucose and lipid metabolism may prevent the development of chronic health conditions such as T2D, CVD and cancer.
Evidence Category:
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X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Management of glucose and lipid metabolism can be achieved through weight reduction using dietary interventions such as very low calorie or CHO diets, which may be effective but difficult to sustain long term. An alternative approach for weight management, improved insulin resistance and subsequent prevention of comorbitities e.g. Type 2 Diabetes (T2D), Cardiovascular Disease (CVD) and cancer, is Intermittent Fasting (IF). such as time restricted or periodic fasting.
This study summarises the effects of IF dietary interventions lasting less than three months in overweight and obese women with Metabolic Syndrome, defined as the presence of any metabolic dysfunction including obesity, hyperglycaemia, dyslipidaemia or hypertension.
The meta-anlaysis was carried out following PRISMA guidelines. A literature search in PubMed and Medline using the keywords obesity/overweight, IF diet, metabolic syndrome, RCT’s and humans resulted in 10 studies with 12 types of intervention for analysis. The following outcomes were evaluated: glucose and lipid metabolism, insulin resistance, weight loss and blood pressure.
Results were analysed in R software using mean differences and 95% confidence intervals, and either random or fixed effects depending on the Cochrane’s Q and I(2) statistics. Funnel plots were inspected for potential bias and Egger’s regression tests for publication bias.
There were significant differences before and after the interventions for all glucose and lipid metabolism markers as well as body weight and systolic blood pressure :
Glucose metabolism:
- Fasting glucose reduced by 0.15mmol/L
- Insulin plasma reduced by 13.25uUI
- HbA1c reduced by 0.08%
- HOMA-IR (insulin resistance index) reduced by 0.31 on average
Lipid metabolism:
- Total cholesterol reduced by 0.32mmol/L
- LDL reduced by 0.22mmol/L
- Triglyceride reduced by 0.04mmol/L
Weight loss:
- Body weight reduced by 1.87kg
- BMI reduced by 0.8kg/m2
- Waist circumference reduced by 2.08cm
Blood pressure:
- Systolic reduced by 2.58mmHg
- Diastolic reduced by 3.12mmHg
Despite limitations of the meta-analysis, this study demonstrates IF has therapeutic effects on those with disordered lipid and glucose metabolism, and may prove to be an effective and sustainable approach.
Clinical practice applications:
- IF may be an effective alternative to restricted calorie or CHO diets for weight management with the associated benefits of glucose and lipid metabolism.
- IF has been shown to have therapeutic effects on individuals with impaired glucose and lipid metabolism.
- IF may be considered as a sustainable lifestyle choice rather than a ‘weight loss’ programme such as a very low calorie diet, which can result in poor quality of life and subsequent reduced adherence.
- Since it may take time for impaired glucose and lipid metabolism to progress to more serious disease states, establishing IF as an early intervention, may be considered as a prudent form of preventative medicine.
- IF has shown to have other health benefits such as reduced blood pressure and may be considered as adjuvant therapy.
Considerations for future research:
- Compares the effects of IF on different ethnicities, sex and age categories
- Evaluates the effect of IF on other disease states e.g. cancer, auto-immune conditions
- Assesses the response of other biomarkers e.g. inflammatory cytokines
- Compares different types and durations of IF on health biomarkers (eg periodic, time restricted)
Abstract
The question of whether or not intermittent fasting diets improve the clinical indicators of glycolipid metabolism remains unclear. This study systematically reviewed the relevant clinical trials to evaluate the effects of intermittent fasting diet on glucose and lipid metabolism and insulin sensitivity in patients with metabolic syndrome. To evaluate the effect of intermittent fasting diet intervention on patients with disorders of glucose and lipid metabolism, random-effect or fixed-effect meta-analysis models were used to calculate the average difference before and after intermittent fasting diet intervention and the corresponding 95% confidence intervals (CIs). After intermittent fasting diet intervention, in terms of glucose metabolism, fasting blood glucose reduced by 0.15 mmol/L (95% CI: -0.23; -0.06), glycosylated hemoglobin reduced by 0.08 (95% CIs: -0.25; -0.10), insulin plasma levels reduced by 13.25 uUI (95% CIs: -16.69; -9.82), and HOMA-IR decreased by 0.31 on an average (95% CIs: -0.44; -0.19). In addition, BMI decreased by 0.8 kg/m2 (95% CIs: -1.32; -0.28), body weight reduced by 1.87 kg (95% CIs: -2.67; -1.07), and the waist circumference decreased by 2.08 cm (95% CIs: -3.06; -1.10). Analysis of lipid metabolism showed that intermittent fasting diet intervention effectively reduced the total cholesterol level by 0.32 mmol/L (95% CIs: -0.60; -0.05), low-density lipoprotein level by 0.22 mmol/L (95% CIs: -0.37; -0.07), and triglyceride level by 0.04 mmol/L (95% CIs: -0.15; -0.07). Intermittent fasting diets have certain therapeutic effects on blood glucose and lipids in patients with metabolic syndrome and significantly improve insulin resistance. It may be considered as an auxiliary treatment to prevent the occurrence and development of chronic diseases.
4.
Effect of sleep duration on dietary intake, desire to eat, measures of food intake and metabolic hormones: A systematic review of clinical trials.
Soltanieh, S, Solgi, S, Ansari, M, Santos, HO, Abbasi, B
Clinical nutrition ESPEN. 2021;45:55-65
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Plain language summary
Adequate sleep is crucial to health. Yet, sleep disturbances have become very common in modern societies. A lack of sleep is linked to increased risk for several chronic diseases such as diabetes, high blood pressure, metabolic syndrome and cardiovascular disease. Furthermore, appetite-regulating hormones can be disrupted by sleep shortages, which is thought to drive chronic overeating, leading to weight gain, obesity and its associated health consequences. This review examined the relationship between sleep duration and food consumption and energy intake, whilst also monitoring changes in body weight and appetite-regulating hormones. The review encompassed 50 randomized controlled trials (RCTs) with 3387 participants, including 1079 children and adolescents and 2308 adults. The findings suggested that sleep shortages contribute to significant increases in calorie intake, fat intake, increased body weight, appetite, hunger, more frequent eating and bigger portion sizes. In this review lack of sleep did not change protein and carbohydrate intake. Nor did lack of sleep make people exert more or less energy overall, however, a variance amongst ethnic groups was observed here. There was not enough evidence for changes in metabolic rate, so the review assumed no significant effect. When viewed collectively, the appetite-regulating hormones of leptin and ghrelin, the stress hormone cortisol and the sugar-regulating hormone insulin were not significantly influenced by sleep duration. However, there seemed to be a wide variance of outcomes when looking at individual studies' results. In conclusion, the authors reiterated the importance of sleep for health maintenance, advocating for a minimum of 7 hours of sleep per day for adults and that, despite busy modern lifestyles, sleep optimisation strategies should be prioritised. Less than 6 hours of sleep per day increases the risk of health consequences, like weight gain and metabolic disorders and sleep management should be considered part of their treatment protocols.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Reduced sleep duration may serve as a mediator for weight gain in part due to increased appetite, increased fat intake and disruptions to energy balance.
- Enhancing sleep quality may serve to support weight loss protocols.
Evidence Category:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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X
B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Introduction
Short sleep duration and disruptions to circadian rhythm have been associated with being overweight and obese. It has been suggested that sleep restriction may interfere with appetite regulating hormones leading to increased appetite and disrupted energy balance.
This study aimed to systematically review studies exploring the relationship between sleep duration and food consumption, energy intake, anthropometric characteristics and appetite-regulating hormones.
Methods
This systematic review included 50 randomised controlled trials including 3,387 participants.
Results
Energy intake
- 13 out of 30 the included studies found that short sleep conditions led to higher energy intake.
- 1 study identified that sleep restriction resulted in a 15.3% and 9.2% increase in energy intake in both women and men.
- 3 studies noted that prolonging sleep duration led to a reduction in energy intake.
- 1 study reported a reduction in energy intake after sleep restriction (P=0.031).
Fat consumption
- 9 studies out of 22 identified a significant association between short sleep and increased fat consumption.
- 7 studies did not identify a difference between groups.
- 3 studies noted a decrease in fat consumption following prolonged sleep (P<0.001, P<0.05, P=0.04).
Hunger and appetite
- 11 studies out of 17 observed that sleep restriction resulted in increased hunger ratings.
- 3 studies found an increase in appetite following sleep restriction (P<0.01) with 3 finding no difference..
- 1 study reported a decrease in appetite following sleep restriction.
- 2 studies noted that portion sizes increased as a result of sleep restriction (P<0.01).
- 1 study reported an increase in eating occasions following restricted sleep compared to habitual sleep (6.08 vs 4.96).
Body weight
- 6 studies out of 14 found no effect of sleep loss on body weight.
- 4 studies identified that sleep restriction led to weight gain (P<0.001, P<0.05, P=0.14, P=0.031).
- 2 studies reported weight loss following increased sleep duration (P<0.001).
Ghrelin and leptin
- Leptin and ghrelin levels were generally not found to be influenced by sleep duration, with the exception of a few studies.
Clinical practice applications:
Reduced sleep duration may promote weight gain by:
- Increasing energy intake.
- Increasing fat consumption.
- Increasing hunger and appetite.
- Increasing portion sizes and eating occasions.
Prolonging sleep duration may support weight loss by:
- Reducing energy intake.
- Reducing fat intake.
Considerations for future research:
- Mixed results on the influence of sleep restriction on appetite regulating hormones, leptin and ghrelin.
- Some studies noted the negative impact of sleep restriction on leptin and ghrelin concentrations, collectively shortened sleep duration did not appear to influence these hormones.
- Further sleep restriction studies exploring additional appetite regulating hormones and neuropeptides and the reward system may provide a more definitive understanding of the underlying mechanism for reduced sleep duration to disrupt the appetite and energy balance and promote weight gain.
Abstract
BACKGROUND AND AIMS Sleep, as well as diet and physical activity, plays a significant role in growth, maturation, health, and regulation of energy homeostasis. Recently, there is increasing evidence indicating a possible causal association between sleep duration and energy balance. We aimed to examine the relationship between sleep duration and food consumption, energy intake, anthropometric characteristics, and appetite-regulating hormones by randomized controlled trials (RCTs). METHODS Electronic literature searches were conducted on Medline, Web of Science, and Google Scholar until July 2020. The search was conducted with the following words: "Sleep Duration", "Circadian Rhythm", "Sleep Disorders" in combination with "Obesity", "Overweight", "Abdominal Obesity", "Physical Activity", "Energy Intake", "Body Mass Index", "Lipid Metabolism", "Caloric Restriction", Leptin, "Weight Gain", and "Appetite Regulation" using human studies.methods RESULTS After screening 708 abstracts, 50 RCTs (7 on children or adolescents and 43 on adults) were identified and met the inclusion criteria. In general, the findings suggested that sleep restriction may leads to a significant increment in energy intake, fat intake, body weight, appetite, hunger, eating occasions, and portion size, while protein and carbohydrate consumption, total energy expenditure, and respiratory quotient remained unaffected as a result of sleep restriction. Serum leptin, ghrelin, and cortisol concentrations were not influenced by sleep duration as well. CONCLUSION Insufficient sleep can be considered as a contributing factor for energy imbalance, weight gain, and metabolic disorders and it is suggested that to tackle disordered eating it may be necessary to pay more attention to sleep duration.