Effects of weight loss through dietary intervention on pain characteristics, functional mobility, and inflammation in adults with elevated adiposity

BackgroundThe relationship between adiposity and pain is complex. Excess weight increases the risk for chronic musculoskeletal pain (CMP), driven by increased biomechanical load and low-grade systemic inflammation. Pain limits physical function, impacting energy balance contributing to weight gain. The primary aims of this study were to profile pain characteristics in participants with overweight or obesity and determine if weight loss through dietary-induced energy restriction, and presence of CMP, or magnitude of weight loss, was associated with changes in adiposity, pain, functional mobility, and inflammation.MethodsThis was a secondary analysis of data from adults (25–65 years) with overweight or obesity (BMI 27.5–34.9 kg/m2) enrolled in a 3-month, 30% energy-restricted dietary intervention to induce weight loss (January 2019–March 2021). Anthropometric measures (weight, waist circumference and fat mass), pain prevalence, pain severity (McGill Pain Questionnaire, MPQ), pain intensity (Visual Analog Scale, VAS), functional mobility (timed up and go, TUG) and inflammation (high sensitivity C-Reactive Protein, hsCRP) were assessed at baseline and 3-months.ResultsOne hundred and ten participants completed the intervention and had weight and pain assessed at both baseline and 3-months. Participants lost 7.0 ± 0.3 kg, representing 7.9% ± 3.7% of body mass. At 3-months, functional mobility improved (TUG −0.2 ± 0.1 s, 95% CI −0.3, −0.1), but there was no change in hsCRP. Compared to baseline, fewer participants reported CMP at 3-months (n = 56, 51% to n = 27, 25%, p < 0.001) and presence of multisite pain decreased from 22.7% to 10.9% (p < 0.001). Improvements in anthropometric measures and functional mobility did not differ between those presenting with or without CMP at baseline. Improvements in pain were not related to the magnitude of weight loss.ConclusionWeight loss was effective in reducing pain prevalence and improving functional mobility, emphasizing the importance of considering weight-loss as a key component of pain management.Clinical trial registrationidentifier, ACTRN12618001861246

Weight-Loss Outcomes: A Systematic Review and Meta-Analysis of Intermittent Energy Restriction Trials Lasting a Minimum of 6 Months

The aim of this systematic review and meta-analysis is to summarise the effects of intermittent energy restriction on weight and biological markers in long term intervention studies of >6 months duration. An electronic search was performed using the MEDLINE, EMBASE and the Cochrane Library databases for intervention trials lasting 6 months or longer investigating the effects of intermittent energy restriction. A total of nine studies were identified as meeting the pre-specified criteria. All studies included an intermittent energy restriction arm, with six being directly compared to continuous energy restriction. A total of 981 subjects were enrolled and randomised, with weight loss observed in all intermittent energy restriction arms regardless of study duration or follow up length. Eight interventions in six trials were used for the meta-analyses, with results indicating neither intermittent or continuous energy restriction being superior with respect to weight loss, 0.084 ± 0.114 (overall mean difference between groups ± standard error; p = 0.458). The effects of intermittent energy restriction in the long term remain unclear. The number of long term studies conducted is very limited, and participant numbers typically small (less than 50 completers), indicating the need for larger, long term trials of 12 months or more, to be conducted in order to understand the impact of intermittent energy restriction on weight loss and long term weight management. Blood lipid concentrations, glucose, and insulin were not altered by intermittent energy expenditure in values greater than those seen with continuous energy restriction

Study protocol for a 15-week randomised controlled trial assessing the independent effects of high-cholesterol and high-saturated fat diets on LDL cholesterol

Introduction Previous research has associated high dietary cholesterol intake with raised low-density lipoprotein cholesterol (LDL-C) and thus increased risk for cardiovascular disease (CVD). Emerging research suggests that it is saturated fat, not dietary cholesterol, associated with increased CVD risk. Despite being high in cholesterol, eggs, low in saturated fat, are not adversely associated with blood lipids or CVD risk. This paper describes a randomised controlled counter-balanced, cross-over trial assessing the effects of a high-cholesterol/low-saturated fat (egg) diet and a low-cholesterol/high-saturated fat diet (egg free) on blood lipids and lipoproteins, while accounting for physical activity levels which can also influence these parameters. The primary aim is to demonstrate that high cholesterol intake (from eggs) within a healthy, low-saturated fat diet does not adversely affect blood lipid levels and lipoprotein profiles. Instead, we propose that adverse effects on these parameters are mediated by saturated fat intake. The secondary aim is to explore relationships between changes in blood lutein and zeaxanthin concentrations and alterations in physical activity, examining whether changes in physical activity mediate effects on blood lipids and lipoproteins.Methods and analysis Fifty-two adults aged 18–60 years with LDL-C less than 3.5 mmol/L will be randomly allocated to three isocaloric diets for 5 weeks each: a high-cholesterol (600 mg)/low-saturated fat (6%) (egg) diet, a low-cholesterol (300 mg)/high-saturated fat (12%) (egg free) diet and a control diet that is high in both cholesterol (600 mg) and saturated fat (12%). Lipid and lipoprotein levels, lipoprotein size and concentrations, blood pressure, blood glucose, physical activity levels, and plasma lutein and zeaxanthin concentrations will be measured. Treatment effects will be analysed using linear mixed effects models.Ethics and dissemination Ethics approval was obtained from the University of South Australia Human Research Ethics Committee no. 204 327. Results will be disseminated through peer-reviewed journals and national and international presentations.Trial registration number NCT0526752