1.
Distribution of energy intake across the day and weight loss: A systematic review and meta-analysis.
Young, IE, Poobalan, A, Steinbeck, K, O'Connor, HT, Parker, HM
Obesity reviews : an official journal of the International Association for the Study of Obesity. 2023;24(3):e13537
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Obesity increases an individual's risk of metabolic disease, such as diabetes and cardiovascular disease, musculoskeletal disorders such as osteoarthritis, and some cancers. “Chrononutrition” relates to the timing of meals and distribution of total energy intake across the day. Evidence is building chrononutrition as a potential target in both weight loss and metabolic disease interventions. The aim of this study was to examine the impact of earlier versus later distribution of total daily energy intake on weight loss, and to evaluate the potential for utilizing altered energy distribution as a tool in weight loss interventions. This study is a systematic review and meta-analysis of nine clinical studies. Total number of participants was 485 (earlier distributed total energy intakes: n = 244, later distributed total energy intakes; n = 241). Results show that energy intakes with a focus on earlier distribution resulted in significantly greater weight loss when compared with similarly energy-restricted diets with individuals consuming a larger proportion of their total energy intake later in the day and into the evening. Authors conclude that earlier energy intakes may be a promising tool to be used in conjunction with other weight loss strategies such as energy restriction to enhance weight loss. However, further research is required to elucidate the additional positive impacts that earlier distributed total energy intakes may have on weight and metabolic health.
Expert Review
Conflicts of interest:
None
Take Home Message:
Implementing a dietary strategy where a higher proportion of energy is consumed earlier in the day may offer additional benefits to an energy restricted diet for weight loss, blood glucose, improve markers of insulin resistance, increase satiety and improve hunger management. Based on the findings, earlier distribution of energy intake may serve as an effective component of a weight loss protocol.
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:
Background
Chrononutrition refers to the timing and distribution of total daily energy intake across the day. It has been proposed that consuming a greater proportion of total daily energy intake earlier in the day as opposed to the evening may be beneficial for weight loss and metabolic health.
Aims
This systematic review and meta-analysis aimed to assess the impact of earlier versus later distribution of total daily energy intake on weight loss.
Results
A total of 9 randomised controlled trials involving 485 participants were included in this analysis. The study durations ranged from 5-16 weeks. All of the studies included in this analysis applied energy-restricted diets to both intervention arms. The mean percentages of energy intake in 8 of the 9 studies per meal were:
- Earlier distributed intakes: breakfast: 34% ± 16%, lunch: 38% ± 7%, dinner: 20% ± 6%.
- Later distributed intakes: breakfast: 19% ± 6%, lunch: 30% ± 10%, dinner; 40% ± 11%.
One of the studies advised percentage of energy intakes as either:
- Earlier: 70% for breakfast, morning tea and lunch and 30% for afternoon tea and dinner
- Late: 55% for breakfast, morning tea and lunch and 45% for afternoon tea and dinner.
The earlier distributed energy intake groups demonstrated significantly greater weight loss when compared with later distributed energy intake groups ( Mean Difference (MD) −1.23 kg; 95% CI −2.40, −0.06, p = 0.04;
I2 = 98%).
The earlier energy intake groups also displayed lower fasting and bedtime glucose levels (fasting: −0.83 vs. −0.27 mmol/L, p = 0.001; before sleep: −1.70 vs. −0.28 mmol/L, p = 0.009).
A random-effects model demonstrated that the earlier intake groups displayed greater reductions in LDL (MD: −0.11 mmol/L; 95% CI −0.14, −0.07, p < 0.01), fasting glucose (MD: 0.15 mmol/L, 95% CI −0.23, −0.06, p < 0.001) and HOMA-IR (MD: −0.38; 95% CI −0.64, −0.11, p = 0.005).
One study reported that earlier distribution energy intake also led to a greater reduction in medications following the intervention for type 2 diabetics (31% vs. 0%, P=0.002).
Two of the studies assessed both appetite and hunger and identified that earlier distribution of energy led to improvements in their urge to eat, preoccupation with food and cravings for sweets and fats.
Clinical practice applications:
Earlier distribution of energy intake may be beneficial for:
- Weight loss
- Improve fasting insulin, HOMA-IR, fasting glucose and HbA1c
- Reducing LDL
- Improving satiety and hunger management
- Supporting the reduction of medications for individuals with type 2 diabetes
- Improving regularity of sleep and waking times
Considerations for future research:
As the included studies only ranged from 5-16 weeks, longer duration studies would be useful to identify the effect of earlier distribution of energy intake on body weight, metabolic health and appetite over a longer period of time. There was a high degree of heterogeneity between the studies and a lack of uniformity in the distributions of energy intake across the day. Further studies with more uniformity of energy distribution would be needed to identify the optimal distribution of energy across the day to improve body weight and metabolic health.
Abstract
Consuming a greater proportion of total energy intake earlier in the day rather than in the evening is proposed to positively influence weight loss and health, potentially due to greater synchronization of human body circadian rhythms. This systematic review provides an update on existing evidence regarding earlier distributed eating patterns in weight loss interventions. Using a robust search strategy in five electronic databases, nine randomized controlled trials investigating the impact of energy intake distribution on weight loss were identified. Following critical appraisal, a random-effects meta-analyses found that, in the context of an energy-reduced diet, distributing energy intake with a focus on earlier intake resulted in significantly greater weight loss (-1.23 kg; 95% CI 2.40, -0.06, p = 0.04). Improvements in HOMA-IR, fasting glucose, and LDL cholesterol were also seen. The current study provides a timely update on the evidence linking distribution of total daily energy intake and health, showing that a focus on earlier intakes can result in greater short-term weight loss compared with later intakes. Future studies are needed to elucidate the impact that earlier intakes may have on weight management and metabolic health.
2.
Dose-response relationship between weight loss and improvements in obstructive sleep apnea severity after a diet/lifestyle interventions: secondary analyses of the "MIMOSA" randomized clinical trial.
Georgoulis, M, Yiannakouris, N, Kechribari, I, Lamprou, K, Perraki, E, Vagiakis, E, Kontogianni, MD
Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine. 2022;18(5):1251-1261
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Obstructive sleep apnoea (OSA) represents one of the most common and serious sleep-related breathing disorders. Excess body weight has emerged as the strongest modifiable predictor of the onset and severity of OSA. The aim of this study was to explore the dose-response relationship between the degree of weight loss and improvements in OSA severity. This study is a secondary analysis of the Mediterranean diet/lifestyle Intervention for the Management of Obstructive Sleep Apnea (MIMOSA) study, which was designed as a single-centre, single-blind, parallel, randomised, controlled clinical trial. Results show that respiratory events and oximetry indices improved only in patients who lost weight and improvements were proportional to the degree of weight loss. Authors conclude that their findings indicate a dose-response relationship between the degree of weight loss and improvement in OSA severity and symptoms. However, further research is needed to gather more data on the optimal degree of weight loss and appropriate weight-loss interventions for managing the wide spectrum of OSA severity to guide clinical practice.
Expert Review
Conflicts of interest:
None
Take Home Message:
Important from a public health perspective:
- This study has confirmed that even a small degree of weight loss can have a beneficial effect on respiratory events and oxygen desaturation in moderate-to-severe OSA, but clinicians should preferably aim at a ≥ 5% weight loss, and ideally a ≥ 10% weight loss, to achieve clinically meaningful reductions in OSA severity.
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
OSA represents one of the most common and serious sleep-related breathing disorders, with a high worldwide prevalence of almost 1 billion people. OSA has numerous well-established cardiometabolic consequences.
The authors highlight that weight loss is essential for obstructive sleep apnea (OSA) management. However, the optimal degree of weight loss for improving OSA severity or eliminating sleep-disordered breathing has not been extensively studied. The aim of this study was to explore the dose-response relationship between the degree of weight loss and improvements in OSA severity.
Methods
This is a secondary analysis of the Mediterranean diet/lifestyle Intervention for the Management of Obstructive Sleep Apnea (MIMOSA) study. This study was designed as a single-center, single-blind, parallel, randomised, controlled clinical trial to evaluate the effectiveness of a weight-loss Mediterranean dietary/lifestyle intervention on managing OSA.
This 6-month long clinical trial included 180 adult, overweight/obese moderate-to-severe OSA patients (45 patients per study group plus a 29% dropout rate). All patients were prescribed the standard of care continuous positive airway pressure (CPAP) therapy and were randomised to 3 arms: standard care; Mediterranean diet; Mediterranean lifestyle
Based on percent change in weight at 6 months, participants were categorised into a weight-stable/gain (WS/GG) group or one of 3 weight-loss groups (WLG): < 5%WLG; 5%–10%WLG; ≥ 10%WLG. Polysomnographic data and OSA symptoms were also evaluated preintervention and postintervention.
Results
Results confirm a dose-response relationship between the degree of weight loss achieved through a dietary/lifestyle intervention and improvements in OSA severity.
- Respiratory events and oximetry indices improved only in patients who lost weight. Improvements were proportional to the degree of weight loss.
- Median percent change in apnea-hypopnea index (AHI) was −11.7%, − 37.9%, and − 49.3% in the < 5%WLG, 5%–10%WLG, and ≥ 10%WLG, respectively (P < .001).
- Compared to the WS/GG, the age-, sex-, baseline-, and CPAP use–adjusted relative risk (95% confidence interval) of severe OSA (AHI ≥ 30 events/h) was 0.45 (0.23–0.87) in the 5%–10%WLG and 0.32 (0.17–0.64) in the ≥ 10%WLG; the risk was also lower in the ≥ 10%WLG vs the < 5%WLG (0.42 [0.22–0.82]).
- Insomnia and daytime sleepiness also improved more in participants exhibiting ≥ 5% weight loss.
- The dose-response relationship between weight loss and improvement in OSA severity was evident regardless of self-reported CPAP use.
Conclusions
The authors conclude that even a < 5% weight loss was sufficient for improvements in respiratory events and oximetry indices, but the prevalence of severe OSA reduced only after a ≥ 5% weight loss, and patients achieving a ≥ 10% weight loss exhibited the greatest benefits compared to weight-stable/gain patients.
Clinical practice applications:
These findings might be useful for Nutritional Therapists and Clinical Practitioners:
- Clinicians should aim for a ≥ 5% weight loss, and ideally a ≥ 10% weight loss, to achieve clinically meaningful reductions in OSA severity.
- Improvements after weight loss were significant even though a healthy body weight was not achieved.
Considerations for future research:
- The study sample consisted of predominantly male, overweight, otherwise healthy patients with moderate-to-severe OSA. Therefore, findings cannot be generalised to the whole OSA population and further research is required with broader, diverse, study samples.
- 6 months is a short duration period, therefore longer trials are required.
- Self-reported CPAP use by participants is a limitation of this study. Further robust analysis methods should be considered for future trials.
- Participants were advised to abstain from CPAP therapy for 2 days prior to the follow-up PSG but this was not evaluated or confirmed in this study and should be in future research.
Abstract
STUDY OBJECTIVES Lifestyle-induced weight loss is a complementary therapeutic approach for obstructive sleep apnea (OSA). We aimed at identifying the dose-response relationship between weight loss and OSA severity improvement. METHODS This is a secondary analysis of a 6-month clinical trial in 180 adult, overweight/obese moderate-to-severe OSA patients. Participants were randomized to a standard care, a Mediterranean diet, or a Mediterranean lifestyle arm. All patients were prescribed with continuous positive airway pressure (CPAP), while intervention arms additionally participated in a weight-loss dietary/lifestyle intervention. Based on percent change in weight at 6 months, participants were categorized into a weight-stable/gain (WS/GG) group or 3 weight-loss groups (WLG): < 5%WLG, 5%-10%WLG, and ≥ 10%WLG. Polysomnographic data and OSA symptoms were evaluated preintervention and postintervention. RESULTS Respiratory events and oximetry indices improved only in patients who lost weight and improvements were proportional to the degree of weight loss. Median percent change in apnea-hypopnea index (AHI) was -11.7%, - 37.9%, and - 49.3% in the < 5%WLG, 5%-10%WLG, and ≥ 10%WLG, respectively (P < .001). Compared to the WS/GG, the age-, sex-, baseline-, and CPAP use-adjusted relative risk (95% confidence interval) of severe OSA (AHI ≥ 30 events/h) was 0.45 (0.23-0.87) in the 5%-10%WLG and 0.32 (0.17-0.64) in the ≥ 10%WLG; the risk was also lower in the ≥ 10%WLG vs the < 5%WLG (0.42 [0.22-0.82]). Insomnia and daytime sleepiness also improved more in participants exhibiting ≥ 5% weight loss. CONCLUSIONS Even a < 5% weight loss can reduce respiratory events, but a ≥ 5% and ideally ≥ 10% weight loss is necessary for reducing the prevalence of severe OSA. CLINICAL TRIAL REGISTRATION Registry: ClinicalTrials.gov; Name: Mediterranean Diet/Lifestyle Intervention in Obstructive Sleep Apnea; URL: https://clinicaltrials.gov/ct2/show/NCT02515357; Identifier: NCT02515357. CITATION Georgoulis M, Yiannakouris N, Kechribari I, et al. Dose-response relationship between weight loss and improvements in obstructive sleep apnea severity after a diet/lifestyle intervention: secondary analyses of the "MIMOSA" randomized clinical trial. J Clin Sleep Med. 2022;18(5):1251-1261.
3.
Eating in the lockdown during the Covid 19 pandemic; self-reported changes in eating behaviour, and associations with BMI, eating style, coping and health anxiety.
Coulthard, H, Sharps, M, Cunliffe, L, van den Tol, A
Appetite. 2021;161:105082
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The Covid-19 pandemic resulted in national lockdowns, which resulted in isolation within people’s homes. This cross-sectional survey examined changes in eating patterns and behaviour during lockdown. Of the 620 participants included in the study, eating higher energy density foods was more common in females with a higher BMI and higher health anxiety. Although there was a change in emotional eating behaviours across the sample as a whole, it was not in the expected direction, with many participants reporting a decrease in emotional eating after the implementation of lockdown. There were also increases in fruit and vegetable consumption and home prepared foods. Many of these behavioural responses were influenced by pre-lockdown tendencies. Therefore, it is important to consider these when understanding coping strategies during lockdown, and how to support clients as we come out of lockdown.
Expert Review
Conflicts of interest:
None
Take Home Message:
- National lockdowns, as seen during the 2020/21 Covid-19 pandemic, impacted eating behaviour and associations with BMI, eating style and health anxiety.
- Given the new nature of this research, it is not clear what impact confounding factors such as food insecurity had on changing eating behaviours.
- Disproportionate risks were seen in certain demographics and in those shielding due to their heightened risk from Covid-19.
- Retrospective and longitudinal studies to monitor the impact of lockdowns on eating behaviour and health anxiety are needed.
Evidence Category:
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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:
The role of eating behaviours and psychological responses during lockdown has become an area of interest, particularly with the uncertainty of going into future lockdowns. With Covid-19, and individual’s responses to it, being a relatively new research topic, there is not yet enough evidence for longitudinal outcomes of the findings in these studies. It is also difficult to ascertain the influence of confounding variables prior to the national lockdown, such as food insecurity, not accounted for due to the unpredictable start to the pandemic. There has also been disproportionate risks between certain demographics and their Covid-19 risk, therefore further research on the impact of this on health anxiety and subsequent eating behaviours is required. This highlights a wider need for continued research on the topic.
Clinical practice applications:
Those who had problematic eating behaviours and higher BMI pre lockdown will need to be supported with healthier coping practices if subsequent lockdowns occur, to prevent health related anxiety and consumption of high energy density foods. Furthermore, those who were shielding in their homes were also more likely to show an increase in emotional eating post lockdown. Therefore, clients who spent a large amount of lockdown shielding will need additional support, to develop coping strategies to prevent risk of emotional eating and health anxiety.
Considerations for future research:
Both retrospective and longitudinal studies monitoring the impact of eating behaviours and health anxiety pre and post lockdown are needed. This will help further the evidence base of the potential role of Covid-19 related health anxiety on eating patterns, coping strategies and dietary choices.
Abstract
The global coronavirus pandemic (Covid 19) resulted in national lockdowns where individuals were asked to isolate in their homes to stop the spread of the disease. Using a cross-sectional survey, the current paper aimed to examine self-reported changes in eating patterns and behaviour during the lockdown in the UK, and associations with BMI, demographic variables, eating styles, health anxiety, food insecurity and coping strategies. Participants (N = 620) were recruited online through social media advertising. The results showed that there were self-reported changes to food consumption during the lockdown across the sample. Increases in consumption of HED (high energy density) snack foods during the lockdown was associated with sex, pre-lockdown eating behaviour (emotional eating and uncontrolled eating), and Covid-specific health anxiety. Increases in positive eating practices such as eating more home prepared foods, and fruits and vegetables, were associated with adaptive coping strategies. Higher emotional eating (EE) during the lockdown was associated with a higher BMI, higher pre-lockdown EE and maladaptive coping strategies. Maladaptive coping strategies moderated the relationship between BMI and EE during the lockdown. In particular a higher BMI was associated with higher EE during the lockdown if an individual also had higher maladaptive coping strategies. These findings suggest that changes to eating behaviour may be part of a wider style of maladaptive or adaptive coping, particularly in those with a history of EE or uncontrolled eating. Preparing individuals to adopt more adaptive coping strategies during lockdown situations may be crucial to improving health during subsequent the lockdown events.