Abstract There is interest in the hypothesis that social norms are a determinant of healthy and unhealthy dietary practices. The objective of our work was to assess the weight of evidence that ...experimentally manipulated information about eating norms influences food intake and choice. This systematic review of experimental studies examined whether providing information about other peoples' eating habits influences food intake or choices. To inform the review, three electronic databases (PsycINFO, MEDLINE, and the Social Sciences Citation Index) were searched during July 2012. A narrative approach was used to synthesize studies that examined the influence of norms on food choice and meta-analyses were used to synthesize the effect that informational eating norms have on quantity of food consumed. Fifteen experimental studies were reviewed. There was evidence that both high intake norms ( Z =3.84; P =0.0001; standardized mean difference 0.41, 95% confidence interval 0.20 to 0.63) and low intake norms ( Z =2.78; P =0.005; standard mean difference –0.35, 95% confidence interval –0.59 to –0.10) exerted moderate influence on amounts of food eaten. There was consistent evidence that norms influenced food choices; norm information indicating that others make low-energy or high-energy food choices significantly increased the likelihood that participants made similar choices. Information about eating norms influences choice and quantity of food eaten, which could be used to promote healthy changes to dietary behavior.
ABSTRACT
Aims This study aimed to assess the effects of opportunistic brief physician advice to stop smoking and offer of assistance on incidence of attempts to stop and quit success in smokers not ...selected by motivation to quit.
Methods We included relevant trials from the Cochrane Reviews of physician advice for smoking cessation, nicotine replacement therapy (NRT), varenicline and bupropion. We extracted data on quit attempts and quit success. Estimates were combined using the Mantel–Haentszel method and heterogeneity assessed with the I2 statistic. Study quality was assessed by method of randomization, allocation concealment and follow‐up blind to allocation.
Results Thirteen studies were included. Compared to no intervention, advice to quit on medical grounds increased the frequency of quit attempts risk ratio (RR) 1.24, 95% confidence interval (CI): 1.16–1.33, but not as much as behavioural support for cessation (RR 2.17, 95% CI 1.52–3.11) or offering NRT (RR 1.68, 95% CI: 1.48–1.89). In a direct comparison, offering assistance generated more quit attempts than giving advice to quit on medical grounds (RR 1.69, 95% CI: 1.24–2.31 for behavioural support and 1.39, 95% CI: 1.25–1.54 for offering medication). There was evidence that medical advice increased the success of quit attempts and inconclusive evidence that offering assistance increased their success.
Conclusions Physicians may be more effective in promoting attempts to stop smoking by offering assistance to all smokers than by advising smokers to quit and offering assistance only to those who express an interest in doing so.
Abstract Weight loss can reduce the health risks associated with being overweight or obese. However, the most effective method of weight loss remains unclear. Some programs emphasize physical ...activity, others diet, but existing evidence is mixed as to whether these are more effective individually or in combination. We aimed to examine the clinical effectiveness of combined behavioral weight management programs (BWMPs) targeting weight loss in comparison to single component programs, using within study comparisons. We included randomized controlled trials of combined BWMPs compared with diet-only or physical activity-only programs with at least 12 months of follow-up, conducted in overweight and obese adults (body mass index ≥25). Systematic searches of nine databases were run and two reviewers extracted data independently. Random effects meta-analyses were conducted for mean difference in weight change at 3 to 6 months and 12 to 18 months using a baseline observation carried forward approach for combined BWMPs vs diet-only BWMPs and combined BWMPs vs physical activity-only BWMPs. In total, eight studies were included, representing 1,022 participants, the majority of whom were women. Six studies met the inclusion criteria for combined BWMP vs diet-only. Pooled results showed no significant difference in weight loss from baseline or at 3 to 6 months between the BWMPs and diet-only arms (–0.62 kg; 95% CI –1.67 to 0.44). However, at 12 months, a significantly greater weight-loss was detected in the combined BWMPs (–1.72 kg; 95% CI –2.80 to –0.64). Five studies met the inclusion criteria for combined BWMP vs physical activity-only. Pooled results showed significantly greater weight loss in the combined BWMPs at 3 to 6 months (–5.33 kg; 95% CI –7.61 to –3.04) and 12 to 18 months (–6.29 kg; 95% CI –7.33 to –5.25). Weight loss is similar in the short-term for diet-only and combined BWMPs but in the longer-term weight loss is increased when diet and physical activity are combined. Programs based on physical activity alone are less effective than combined BWMPs in both the short and long term.
Obesity is a major risk factor for adverse outcomes after infection with SARS-CoV-2. We aimed to examine this association, including interactions with demographic and behavioural characteristics, ...type 2 diabetes, and other health conditions.
In this prospective, community-based, cohort study, we used de-identified patient-level data from the QResearch database of general practices in England, UK. We extracted data for patients aged 20 years and older who were registered at a practice eligible for inclusion in the QResearch database between Jan 24, 2020 (date of the first recorded infection in the UK) and April 30, 2020, and with available data on BMI. Data extracted included demographic, clinical, clinical values linked with Public Health England's database of positive SARS-CoV-2 test results, and death certificates from the Office of National Statistics. Outcomes, as a proxy measure of severe COVID-19, were admission to hospital, admission to an intensive care unit (ICU), and death due to COVID-19. We used Cox proportional hazard models to estimate the risk of severe COVID-19, sequentially adjusting for demographic characteristics, behavioural factors, and comorbidities.
Among 6 910 695 eligible individuals (mean BMI 26·78 kg/m2 SD 5·59), 13 503 (0·20%) were admitted to hospital, 1601 (0·02%) to an ICU, and 5479 (0·08%) died after a positive test for SARS-CoV-2. We found J-shaped associations between BMI and admission to hospital due to COVID-19 (adjusted hazard ratio HR per kg/m2 from the nadir at BMI of 23 kg/m2 of 1·05 95% CI 1·05–1·05) and death (1·04 1·04–1·05), and a linear association across the whole BMI range with ICU admission (1·10 1·09–1·10). We found a significant interaction between BMI and age and ethnicity, with higher HR per kg/m2 above BMI 23 kg/m2 for younger people (adjusted HR per kg/m2 above BMI 23 kg/m2 for hospital admission 1·09 95% CI 1·08–1·10 in 20–39 years age group vs 80–100 years group 1·01 1·00–1·02) and Black people than White people (1·07 1·06–1·08 vs 1·04 1·04–1·05). The risk of admission to hospital and ICU due to COVID-19 associated with unit increase in BMI was slightly lower in people with type 2 diabetes, hypertension, and cardiovascular disease than in those without these morbidities.
At a BMI of more than 23 kg/m2, we found a linear increase in risk of severe COVID-19 leading to admission to hospital and death, and a linear increase in admission to an ICU across the whole BMI range, which is not attributable to excess risks of related diseases. The relative risk due to increasing BMI is particularly notable people younger than 40 years and of Black ethnicity.
NIHR Oxford Biomedical Research Centre.
Both the global average per capita consumption of meat and the total amount of meat consumed are rising, driven by increasing average individual incomes and by population growth. The consumption of ...different types of meat and meat products has substantial effects on people's health, and livestock production can have major negative effects on the environment. Here, we explore the evidence base for these assertions and the options policy-makers have should they wish to intervene to affect population meat consumption. We highlight where more research is required and the great importance of integrating insights from the natural and social sciences.
Reducing meat consumption can help prevent non-communicable diseases and protect the environment. Interventions targeting conscious determinants of human behaviour are generally acceptable approaches ...to promote dietary change, but little is known about their effectiveness to reduce the demand for meat.
To evaluate the effectiveness of interventions targeting conscious determinants of human behaviour to reduce the demand for meat.
We searched six electronic databases on the 31st of August 2017 with a predefined algorithm, screened publicly accessible resources, contacted authors, and conducted forward and backward reference searches. Eligible studies employed experimental designs to evaluate interventions targeting conscious determinants of human behaviour to reduce the consumption, purchase, or selection of meat in comparison to a control condition, a baseline period, or relative to other eligible interventions. We synthesised results narratively and conducted an exploratory crisp-set Qualitative Comparative Analysis to identify combinations of intervention characteristics associated with significant reductions in the demand for meat.
We included 24 papers reporting on 59 interventions and 25,477 observations. Self-monitoring interventions and individual lifestyle counselling led to, or were associated with reduced meat consumption. Providing information about the health or environmental consequences of eating meat was associated with reduced intentions to consume and select meat in virtual environments, but there was no evidence to suggest this approach influenced actual behaviour. Education about the animal welfare consequences of eating meat was associated with reduced intentions to consume meat, while interventions implicitly highlighting animal suffering were not. Education on multiple consequences of eating meat led to mixed results. Tailored education was not found to reduce actual or intended meat consumption, though few studies assessed this approach.
Some interventions targeting conscious determinants of human behaviour have the potential to reduce the demand for meat. In particular, self-monitoring interventions and individual lifestyle counselling can help to reduce meat consumption. There was evidence of effectiveness of some educational messages in reducing intended consumption and selection of meat in virtual environments.
CRD42017076720 .
Background: Cognitive processes such as attention and memory may influence food intake, but the degree to which they do is unclear.Objective: The objective was to examine whether such cognitive ...processes influence the amount of food eaten either immediately or in subsequent meals.Design: We systematically reviewed studies that examined experimentally the effect that manipulating memory, distraction, awareness, or attention has on food intake. We combined studies by using inverse variance meta-analysis, calculating the standardized mean difference (SMD) in food intake between experimental and control groups and assessing heterogeneity with the I2 statistic.Results: Twenty-four studies were reviewed. Evidence indicated that eating when distracted produced a moderate increase in immediate intake (SMD: 0.39; 95% CI: 0.25, 0.53) but increased later intake to a greater extent (SMD: 0.76; 95% CI: 0.45, 1.07). The effect of distraction on immediate intake appeared to be independent of dietary restraint. Enhancing memory of food consumed reduced later intake (SMD: 0.40; 95% CI: 0.12, 0.68), but this effect may depend on the degree of the participants’ tendencies toward disinhibited eating. Removing visual information about the amount of food eaten during a meal increased immediate intake (SMD: 0.48; 95% CI: 0.27, 0.68). Enhancing awareness of food being eaten may not affect immediate intake (SMD: 0.09; 95% CI: −0.42, 0.35).Conclusions: Evidence indicates that attentive eating is likely to influence food intake, and incorporation of attentive-eating principles into interventions provides a novel approach to aid weight loss and maintenance without the need for conscious calorie counting.
Anecdotal reports suggest waterpipe smoking is becoming common in students in western countries. The aim was to examine prevalence, risk factors, symptoms of addiction, and smoke intake.
This was a ...cross-sectional survey of students with subsidiary survey of regular waterpipe user and survey of exhaled carbon monoxide (CO) before and after waterpipe smoking in customers of a waterpipe café. 937 students of Birmingham University completed the initial survey with a follow up of 21 regular waterpipe smokers. 63 customers of a waterpipe café near the University completed the study of CO intake.
355 (37.9%, 95% confidence intervals (CI) 34.8 to 41.1%) students had tried waterpipes, the prevalence of trying rising with duration at University. 75 (8.0%, 95%CI 6.4 to 10.0%) were regular smokers, similar to the prevalence of cigarette smoking (9.4%). Although cigarette smoking was the major risk factor for being a regular waterpipe smoker, odds ratio (95%CI) 2.77 (1.52 to 5.06), 65% of waterpipe smokers did not smoke cigarettes. Seven of 21 (33.3%) regular waterpipe smokers experienced cravings. Nearly all regular waterpipe users thought it less harmful than smoking cigarettes. The mean (standard deviation) rise in CO was 37.4 (25.8)ppm, nearly twice as high as a typical cigarette smoker seeking cessation treatment.
Waterpipe smoking is a common part of student culture in one British university, as in the Middle East and in the United States. It poses a potential threat to public health, with evidence of dependence and high smoke intake.
Waterpipe smoking is becoming popular among western students. The aim was to understand the appeal to students of this form of smoking when other forms of smoking are becoming less common.
Waterpipe ...smokers were identified by snowball sampling and interviewed following a semi-structured schedule in waterpipe cafes and in their homes. Constant comparative analysis was used to derive themes for the analysis.
Waterpipe smokers saw smoking as an alternative to more expensive nights out in bars. The appeal was related to the communal activity and the novelty of the experience. Respondents had not thought deeply about the health risks and reasoned that if no warnings about waterpipe smoking were apparent (unlike cigarette smoking) then it was probably safe. These observations were reinforced by observations about the mildness of the smoke, the fruit flavours, and beliefs about the filtering of the water. Waterpipe smokers felt no pressure to stop smoking and therefore had not tried to do so, but felt it might be something they did not continue after university. Waterpipe smoking was not linked in students' minds to other forms of smoking except in one individual who was using waterpipe smoking to help quit cigarettes.
In the absence of public health information, students have fallen back on superficial experiences to form views that waterpipe smoking is less harmful than other forms of smoking and it is currently much more acceptable in student society than other forms of smoking.
Aims
This paper provides a concise review of the efficacy, effectiveness and affordability of health‐care interventions to promote and assist tobacco cessation, in order to inform national guideline ...development and assist countries in planning their provision of tobacco cessation support.
Methods
Cochrane reviews of randomized controlled trials (RCTs) of major health‐care tobacco cessation interventions were used to derive efficacy estimates in terms of percentage‐point increases relative to comparison conditions in 6–12‐month continuous abstinence rates. This was combined with analysis and evidence from ‘real world’ studies to form a judgement on the probable effectiveness of each intervention in different settings. The affordability of each intervention was assessed for exemplar countries in each World Bank income category (low, lower middle, upper middle, high). Based on World Health Organization (WHO) criteria, an intervention was judged as affordable for a given income category if the estimated extra cost of saving a life‐year was less than or equal to the per‐capita gross domestic product for that category of country.
Results
Brief advice from a health‐care worker given opportunistically to smokers attending health‐care services can promote smoking cessation, and is affordable for countries in all World Bank income categories (i.e. globally). Proactive telephone support, automated text messaging programmes and printed self‐help materials can assist smokers wanting help with a quit attempt and are affordable globally. Multi‐session, face‐to‐face behavioural support can increase quit success for cigarettes and smokeless tobacco and is affordable in middle‐ and high‐income countries. Nicotine replacement therapy, bupropion, nortriptyline, varenicline and cytisine can all aid quitting smoking when given with at least some behavioural support; of these, cytisine and nortriptyline are affordable globally.
Conclusions
Brief advice from a health‐care worker, telephone helplines, automated text messaging, printed self‐help materials, cytisine and nortriptyline are globally affordable health‐care interventions to promote and assist smoking cessation. Evidence on smokeless tobacco cessation suggests that face‐to‐face behavioural support and varenicline can promote cessation.