Childhood transitions between weight status categories: evidence from the UK Millennium Cohort Study

Background: Assessing the cost-effectiveness of interventions targeting childhood excess weight requires estimates of the hazards of transitioning between weight status categories. Current estimates are based on studies characterized by insufficient sample sizes, a lack of national representativeness, and untested assumptions. Objectives: We sought to (1) estimate transition probabilities and hazard ratios for transitioning between childhood weight status categories, (2) test the validity of the underlying assumption in the literature that transitions between childhood bodyweight categories are time-homogeneous, (3) account for complex sampling procedures when deriving nationally representative transition estimates, and (4) explore the impact of child, maternal, and sociodemographic characteristics. Methods: We applied a multistate transition modeling approach accounting for complex survey design to UK Millennium Cohort Study (MCS) data to predict transition probabilities and hazard ratios for weight status movements for children aged 3–17. Surveys were conducted at ages 3 (wave 2 in 2004), 5 (wave 3 in 2006), 7 (wave 4 in 2008), 11 (wave 5 in 2012), 14 (wave 6 in 2015), and 17 (wave 7 in 2018) years. We derived datasets that included repeated body mass index measurements across waves after excluding multiple births and children with missing or implausible bodyweight records. To account for the stratified cluster sample design of the MCS, we incorporated survey weights and jackknife replicates of survey weights. Using a validation dataset from the MCS, we tested the validity of our models. Finally, we estimated the relationships between state transitions and child, maternal, and sociodemographic factors. Results: The datasets for our primary analysis consisted of 10,399 children for waves 2–3, 10,729 for waves 3–4, 9685 for waves 4–5, 8593 for waves 5–6, and 7085 for waves 6–7. All datasets consisted of roughly equal splits of boys and girls. Under the assumption of time-heterogeneous transition rates (our base-case model), younger children (ages 3–5 and 5–7 years) had significantly higher annual transition probabilities of moving from healthy weight to overweight (0.033, 95% confidence interval [CI] 0.026–0.041, and 0.027, 95% CI 0.021–0.033, respectively) compared to older children (0.015, 95% CI 0.012–0.018, at ages 7–11; 0.018, 95% CI 0.013–0.023, at ages 11–14; and 0.018, 95% CI 0.013–0.025 at ages 14–17 years). However, the resolution of unhealthy weight was more strongly age-dependent than transitions from healthy weight to non-healthy weight states. Transition hazards differed by child, maternal, and sociodemographic factors. Conclusions: Our models generated estimates of bodyweight status transitions in a representative UK childhood population. Compared to our scenario models (i.e., time-homogeneous transition rates), our base-case model fits the observed data best, indicating a non-time-homogeneous pattern in transitions between bodyweight categories during childhood. Transition hazards varied significantly by age and across subpopulations, suggesting that conducting subgroup-specific cost-effectiveness analyses of childhood weight management interventions will optimize decision-making

Dose–response effect of a whey protein preload on within-day energy intake in lean subjects

The effect of consuming different amounts of whey protein on appetite and energy intake was investigated in two separate studies using randomised, crossover designs. Healthy-weight men and women (range: BMI 19·0–25·0 kg/m2, age 19·4–40·4 years) consumed one of four 400 ml liquid preloads, followed by an ad libitum test meal 90 min later. In study 1, preloads were 1675 kJ with 12·5, 25 or 50 % of energy from protein, and in study 2, preloads were 1047 kJ with 10, 20 or 40 % energy from protein. Flavoured water was used as the control in both the studies. Appetite ratings were collected immediately before 30, 60 and 90 min after consuming the preloads; and immediately, 30 and 60 min after consuming the test meal. In study 1, energy intake following the control preload (4136 (sem 337) kJ) was significantly higher than each of the 12·5 % (3520 (sem 296) kJ), 25 % (3384 (sem 265) kJ) and 50 % (2853 (sem 244) kJ) protein preloads (P < 0·05). Intake after the 12·5 % preload was significantly higher than following 25 and 50 % preloads (P < 0·05). In study 2, energy intake following the control preload (4801 (sem 325) kJ) was higher than following the 10 % (4205 (sem 310) kJ), 20 % (3988 (sem 250) kJ) and 40 % (3801 (sem 245) kJ) protein preloads (P < 0·05). There were no differences in subjective appetite ratings between preloads in either study. These findings indicate a dose–response effect of protein content of the preload on energy intake at a subsequent meal

Skipping Breakfast Leads to Weight Loss but Also Elevated Cholesterol Compared with Consuming Daily Breakfasts of Oat Porridge or Frosted Cornflakes in Overweight Individuals: A Randomised Controlled Trial

Eating breakfast may reduce appetite, body weight and CVD risk factors, but the breakfast type that produces the greatest health benefits remains unclear. We compared the effects of consuming a high-fibre breakfast, a non-fibre breakfast, or no-breakfast control on body weight, CVD risk factors and appetite. A total of thirty-six overweight participants (eighteen men and eighteen women) (mean age 33·9 (SD 7·5) years, mean BMI 32·8 (SD 4·7) kg/m2) were randomly assigned to consume oat porridge (n = 12), frosted cornflakes (n = 12) or a water control (n = 12) breakfast daily for 4 weeks. Appetite ratings were collected on the first day and weekly thereafter. Before and after the intervention, body weight, composition, blood pressure and resting energy expenditure (REE) were measured and a fasting blood sample was collected. Across the 4 weeks, fullness was higher and hunger was lower in the oat porridge group compared with the control group (P \u3c 0·05). Mean weight change over the intervention was significantly different in the control group (−1·18 (SD 1·16) kg) compared with both the cornflakes (−0·12 (SD 1·34) kg) and oat porridge (+0·26 (SD 0·91) kg) groups (P \u3c 0·05). However, the control group also showed elevated total cholesterol concentrations relative to the cornflakes and oat porridge groups (P \u3c 0·05). There were no differences between groups in changes in body composition, blood pressure, REE or other CVD risk factors. In conclusion, although skipping breakfast led to weight loss, it also resulted in increased total cholesterol concentrations compared with eating either oat porridge or frosted cornflakes for breakfast

Association of gestational diabetes with long‐term risk of premature mortality, and cardiovascular outcomes and risk factors: A retrospective cohort analysis in the UK Biobank

Aim: To investigate the association of gestational diabetes mellitus (GDM) with premature mortality and cardiovascular (CVD) outcomes and risk factors. Materials and Methods: Parous women recruited to the UK Biobank cohort during 2006‐2010 were followed up from their first delivery until 31 October 2021. The data were linked to Hospital Episode Statistics and mortality registries. Multivariate Cox proportional hazard models investigated associations of GDM with all‐cause mortality, CVD, diabetes, hypertension and dyslipidaemia. Results: The maximum total analysis time at risk and under observation was 9 694 090 person‐years. Among 220 726 women, 1225 self‐reported or had a recorded diagnosis of GDM. After adjusting for confounders and behavioural factors, GDM was associated with increased risk for premature mortality [hazard ratio (HR): 1.44, 95% confidence interval (CI): 1.12‐1.86], particularly CVD‐related death (HR: 2.38, 95% CI: 1.63‐3.48), as well as incident total CVD (HR: 1.50, 95% CI: 1.30‐1.74), non‐fatal CVD (HR: 1.41, 95% CI: 1.20‐1.65), diabetes (HR: 14.37, 95% CI: 13.51‐15.27), hypertension (HR: 1.49, 95% CI: 1.38‐1.60), and dyslipidaemia (HR: 1.30, 95% CI: 1.22‐1.39). The total CVD risk was greater in women with GDM who did not later develop diabetes than in those with GDM and diabetes. Conclusions: Women with GDM are at increased risk of premature death and have increased CV risk, emphasizing the importance of interventions to prevent GDM. If GDM develops, the diagnosis represents an opportunity for future surveillance and intervention to reduce CVD risk factors, prevent CVD and improve long‐term health

Replacing meat with alternative plant-based products (RE-MAP):a randomized controlled trial of a multicomponent behavioral intervention to reduce meat consumption

BACKGROUND: Reducing meat consumption could protect the environment and human health. OBJECTIVES: We tested the impact of a behavioral intervention to reduce meat consumption. METHODS: Adult volunteers who regularly consumed meat were recruited from the general public and randomized 1:1 to an intervention or control condition. The intervention comprised free meat substitutes for 4 weeks, information about the benefits of eating less meat, success stories, and recipes. The control group received no intervention or advice on dietary change. The primary outcome was daily meat consumption after 4 weeks, assessed by a 7-day food diary, and repeated after 8 weeks as a secondary outcome. Other secondary and exploratory outcomes included the consumption of meat substitutes, cardiovascular risk factors, psychosocial variables related to meat consumption, and the nutritional composition of the diet. We also estimated the intervention's environmental impact. We evaluated the intervention using generalized linear mixed-effects models. RESULTS: Between June 2018 and October 2019, 115 participants were randomized. The baseline meat consumption values were 134 g/d in the control group and 130 g/d in the intervention group. Relative to the control condition, the intervention reduced meat consumption at 4 weeks by 63 g/d (95% CI: 44–82; P < 0.0001; n = 114) and at 8 weeks by 39 g/d (95% CI: 16–62; P = 0.0009; n = 113), adjusting for sex and baseline consumption. The intervention significantly increased the consumption of meat substitutes without changing the intakes of other principal food groups. The intervention increased intentions, positive attitudes, perceived control, and subjective norms of eating a low-meat diet and using meat substitutes, and decreased attachment to meat. At 8 weeks, 55% of intervention recipients identified as meat eaters, compared to 89% of participants in the control group. CONCLUSIONS: A behavioral program involving free meat substitutes can reduce meat intake and change psychosocial constructs consistent with a sustained reduction in meat intake

Use of cognitive and behavioral strategies during a weight loss program: a secondary analysis of the Doctor Referral of Overweight People to Low-Energy Total Diet Replacement Treatment (DROPLET) trial

Background: Achieving a sustained energy deficit is essential for weight loss, but the cognitive and behavioral strategies that support this goal are unclear. Objective: The goal of this study was to investigate the number and type of cognitive and behavioral strategies used by participants who were enrolled in a 1-year weight loss trial and to explore associations between strategies and magnitude of weight loss at 3 months and 1 year. Design: The study is a secondary post-hoc exploratory analysis of data collected as part of the Doctor Referral of Overweight People to Low-Energy total diet replacement Treatment (DROPLET), a randomized controlled trial conducted in general practices in England, United Kingdom, between January 2016 and August 2017. Participants/setting: This study involved 164 participants from both intervention and control groups of the DROPLET trial who completed the Oxford Food and Behaviours (OxFAB) questionnaire to assess the use of 115 strategies grouped into 21 domains used to manage their weight. Interventions: Participants were randomized to either a behavioral weight loss program involving 8 weeks total diet replacement (TDR) and 4 weeks of food reintroduction or a program delivered by a medical practice nurse over a 3-month period (usual care [UC]). Main outcome measures: Weight was objectively measured at baseline, 3 months, and 1 year. Cognitive and behavioral strategies used to support weight loss were assessed using the OxFAB questionnaire at 3 months. Statistical analysis performed: Exploratory factor analysis was used to generate data-driven patterns of strategy use, and a linear mixed-effects model was used to examine associations between use of these patterns and weight change. Results: No evidence was found of a difference in the number of strategies (mean difference, 2.41; 95% confidence interval [CI], −0.83, 5.65) or the number of domains used (mean difference, −0.23; 95% CI, −0.69, 0.23) between the TDR group and the UC group. The number of strategies was not associated with weight loss at either 3 months (−0.02 kg; 95% CI, −0.11, 0.06) or 1 year (−0.05 kg; 95% CI, −0.14, 0.02). Similarly, the number of domains used was not associated with weight loss at 3 months (−0.02 kg; 95% CI, −0.53, 0.49) or 1 year (−0.07 kg; 95% CI, −0.60, 0.46). Factor analysis identified four coherent patterns of strategy use, identified as Physical Activity, Motivation, Planned Eating, and Food Purchasing patterns. Greater use of strategies in the Food Purchasing (−2.6 kg; 95% CI, −4.42, −0.71) and Planned Eating patterns (−3.20 kg; 95% CI, −4.94, −1.46) was associated with greater weight loss at 1 year. Conclusions:The number of cognitive and behavioral strategies or domains used does not appear to influence weight loss, but the types of strategy appear of greater importance. Supporting people to adopt strategies linked to planned eating and food purchasing may aid long-term weight loss

Binge eating (BE) and obesity: brain activity and psychological measures before and after Roux-en-Y gastric bypass (RYBG)

Brain activity in response to food cues following Roux-En-Y Gastric Bypass (RYGB) in binge eating (BE) or non-binge eating (NB) individuals is understudied. Here, 15 RYGB (8 BE; 7 NB) and 13 no treatment (NT) (7 BE; 6 NB) women with obesity underwent fMRI imaging while viewing high and low energy density food (HEF and LEF, respectively) and non-food (NF) visual cues. A region of interest (ROI) analysis compared BE participants to NB participants in those undergoing RYGB surgery pre-surgery and 4 months post. Results were corrected for multiple comparisons using liberal (p < 0.006 uncorrected) and stringent (p < 0.05 FDR corrected) thresholds. Four months following RYGB (vs. no treatment (NT) control), both BE and NB participants showed greater reductions in blood oxygen level-dependent (BOLD) signals (a proxy of local brain activity) in the dorsomedial prefrontal cortex in response to HEF (vs. LEF) cues (p < 0.006). BE (vs. NB) participants showed greater increases in the precuneus (p < 0.006) and thalamic regions (p < 0.05 corrected) to food (vs. NF). For RYGB (vs. NT) participants, BE participants, but not NB participants, showed lower BOLD signal in the middle occipital gyrus (p < 0.006), whilst NB participants, but not BE participants, showed lower signal in inferior frontal gyrus (p < 0.006) in response to HEF (vs. LEF). Results suggest distinct neural mechanisms of RGYB in BE and may help lead to improved clinical treatments

Effectiveness of behavioural interventions with motivational interviewing on physical activity outcomes in adults: systematic review and meta-analysis

Objective: To evaluate the effectiveness of behavioural interventions that include motivational interviewing on physical activity outcomes in adults. Design: Systematic review and meta-analysis. Study selection: A search of seven databases for randomised controlled trials published from inception to 1 March 2023 comparing a behavioural intervention including motivational interviewing with a comparator without motivational interviewing on physical activity outcomes in adults. Outcomes of interest were differences in change in quantitative measures of total physical activity, moderate to vigorous physical activity (MVPA), and sedentary time. Data extraction and synthesis: Two reviewers extracted data and assessed risk of bias. Population characteristics, intervention components, comparison groups, and outcomes of studies were summarised. For overall main effects, random effects meta-analyses were used to report standardised mean differences (SMDs) and 95% confidence intervals (CIs). Differential effects based on duration of follow-up, comparator type, intervention duration, and disease or health condition of participants were also examined. Results: 129 papers reporting 97 randomised controlled trials totalling 27 811 participants and 105 comparisons were included. Interventions including motivational interviewing were superior to comparators for increases in total physical activity (SMD 0.45, 95% CI 0.33 to 0.65, equivalent to 1323 extra steps/day; low certainty evidence) and MVPA (0.45, 0.19 to 0.71, equivalent to 95 extra min/week; very low certainty evidence) and for reductions in sedentary time (−0.58, −1.03 to −0.14, equivalent to −51 min/day; very low certainty evidence). Evidence for a difference in any outcome compared with comparators of similar intensity was lacking. The magnitude of effect diminished over time, and evidence of an effect of motivational interviewing beyond one year was lacking. Most interventions involved patients with a specific health condition, and evidence of an effect of motivational interviewing to increase MVPA or decrease sedentary time was lacking in general population samples. Conclusions: Certainty of the evidence using motivational interviewing as part of complex behavioural interventions for promoting total physical activity in adults was low, and for MVPA and sedentary time was very low. The totality of evidence suggests that although interventions with motivational interviewing increase physical activity and decrease sedentary behaviour, no difference was found in studies where the effect of motivational interviewing could be isolated. Effectiveness waned over time, with no evidence of a benefit of motivational interviewing to increase physical activity beyond one year. Systematic review registration: PROSPERO CRD42020219881

A systematic review of economic evaluations of interventions targeting childhood overweight and obesity

This systematic review critically appraised and synthesized evidence from economic evaluations of interventions targeting childhood excess weight. We conducted systematic searches in 11 databases from inception to April 19, 2023. Studies were eligible if they evaluated interventions targeting children up to 18 years and the study intervention(s) targeted childhood excess weight or sought to improve diet or physical activity, regardless of the type of economic evaluation or the underpinning study design. We synthesized evidence using narrative synthesis methods. One-hundred fifty-one studies met the eligibility criteria and were classified into three groups based on the intervention approach: prevention-only (13 studies), prevention and treatment (100 studies), and treatment-only (38 studies). The predominant setting and study design differed considerably between the three groups of studies. However, compared with usual care, most interventions were deemed cost-effective. The study participants' ages, sex, and socioeconomic status were crucial to intervention cost-effectiveness. Interventions whose effects were projected beyond childhood, such as bariatric surgery, lower protein infant formula, and home-based general practitioner consultations, tended to be cost-effective. However, cost-effectiveness was sensitive to the assumptions underlying the persistence and intensity of such effects. Our findings can inform future recommendations on the conduct of economic evaluations of interventions targeting childhood overweight and obesity, as well as practice and policy recommendations

Associations of BMI with COVID-19 vaccine uptake, vaccine effectiveness, and risk of severe COVID-19 outcomes after vaccination in England: a population-based cohort study

Background: A high BMI has been associated with a reduced immune response to vaccination against influenza. We aimed to investigate the association between BMI and COVID-19 vaccine uptake, vaccine effectiveness, and risk of severe COVID-19 outcomes after vaccination by using a large, representative population-based cohort from England. Methods: In this population-based cohort study, we used the QResearch database of general practice records and included patients aged 18 years or older who were registered at a practice that was part of the database in England between Dec 8, 2020 (date of the first vaccination in the UK), to Nov 17, 2021, with available data on BMI. Uptake was calculated as the proportion of people with zero, one, two, or three doses of the vaccine across BMI categories. Effectiveness was assessed through a nested matched case-control design to estimate odds ratios (OR) for severe COVID-19 outcomes (ie, admission to hospital or death) in people who had been vaccinated versus those who had not, considering vaccine dose and time periods since vaccination. Vaccine effectiveness against infection with SARS-CoV-2 was also investigated. Multivariable Cox proportional hazard models estimated the risk of severe COVID-19 outcomes associated with BMI (reference BMI 23 kg/m2) after vaccination. Findings: Among 9 171 524 participants (mean age 52 [SD 19] years; BMI 26·7 [5·6] kg/m2), 566 461 tested positive for SARS-CoV-2 during follow-up, of whom 32 808 were admitted to hospital and 14 389 died. Of the total study sample, 19·2% (1 758 689) were unvaccinated, 3·1% (287 246) had one vaccine dose, 52·6% (4 828 327) had two doses, and 25·0% (2 297 262) had three doses. In people aged 40 years and older, uptake of two or three vaccine doses was more than 80% among people with overweight or obesity, which was slightly lower in people with underweight (70–83%). Although significant heterogeneity was found across BMI groups, protection against severe COVID-19 disease (comparing people who were vaccinated vs those who were not) was high after 14 days or more from the second dose for hospital admission (underweight: OR 0·51 [95% CI 0·41–0·63]; healthy weight: 0·34 [0·32–0·36]; overweight: 0·32 [0·30–0·34]; and obesity: 0·32 [0·30–0·34]) and death (underweight: 0·60 [0·36–0·98]; healthy weight: 0·39 [0·33–0·47]; overweight: 0·30 [0·25–0·35]; and obesity: 0·26 [0·22–0·30]). In the vaccinated cohort, there were significant linear associations between BMI and COVID-19 hospitalisation and death after the first dose, and J-shaped associations after the second dose. Interpretation: Using BMI categories, there is evidence of protection against severe COVID-19 in people with overweight or obesity who have been vaccinated, which was of a similar magnitude to that of people of healthy weight. Vaccine effectiveness was slightly lower in people with underweight, in whom vaccine uptake was also the lowest for all ages. In the vaccinated cohort, there were increased risks of severe COVID-19 outcomes for people with underweight or obesity compared with the vaccinated population with a healthy weight. These results suggest the need for targeted efforts to increase uptake in people with low BMI (<18·5 kg/m2), in whom uptake is lower and vaccine effectiveness seems to be reduced. Strategies to achieve and maintain a healthy weight should be prioritised at the population level, which could help reduce the burden of COVID-19 disease. Funding: UK Research and Innovation and National Institute for Health Research Oxford Biomedical Research Centre