Modelling population responses to workplace minimum dietary standards introduced as workers return after social lockdowns.

BACKGROUND: Diet norms are the shared social behaviours and beliefs about diets. In many societies, including the UK, these norms are typically linked to unhealthy diets and impede efforts to improve food choices. Social interactions that could influence one another's food choices, were highly disrupted during the lockdowns in response to the COVID-19 pandemic. A return to workplaces and re-establishment of eating networks may present an opportunity to influence dietary norms by introducing minimum dietary standards to in workplaces, which could then spread through wider home and workplace networks. METHODS: An agent-based model was constructed to simulate a society reflecting the structure of a city population (1000 households) to explore changes in personal and social diet-related norms. The model tracked individual meal choices as agents interact in home, work or school settings and recorded changes in diet quality (range 1 to 100). Scenarios were run to compare individuals' diet quality with the introduction of minimum dietary standards with degrees of working from home. RESULTS: The more people mixed at work the greater the impact of minimum standards on improving diet norms. Socially isolated households remained unaffected by minimum standards, whereas household members exposed directly, in workplaces or schools, or indirectly, influenced by others in the household, had a large and linear increase in diet quality in relation to minimum standards (0.48 [95% CI 0.34, 0.62] per unit increase in minimum standards). Since individuals regressed to the new population mean, a small proportion of diets decreased toward lower population norms. The degree of return to work influenced the rate and magnitude of change cross the population (-2.4 points [-2.40, -2.34] in mean diet quality per 20% of workers isolating). CONCLUSIONS: These model results illustrate the qualitative impact social connectivity could have on changing diets through interventions. Norms can be changed more in a more connected population, and social interactions spread norms between contexts and amplified the influence of, for example, workplace minimum standards beyond those directly exposed. However, implementation of minimum standards in a single type of setting would not reach the whole population and in some cases may decrease diet quality. Any non-zero standard could yield improvements beyond the immediate adult workforce and this could spill between social contexts, but would be contingent on population connectivity.

The effects of minimum unit pricing for alcohol on food purchases: Evaluation of a natural experiment.

Background: On the 1st of May 2018 Scotland became the first country to introduce minimum unit pricing (MUP) for alcohol sales. The objective of this study is to identify the effects of this policy instrument on food purchasing by evaluating a natural experiment. Methods: Longitudinal analysis compares regions with similar characteristics but differing exposure to MUP (Scotland and the north of England). Secondary data from the Kantar Worldpanel on itemised purchases between April 2017 and April 2019 provided a total sample of 8051 households. The outcomes analysed are weekly household expenditure (£s) and purchase volume (grams), both overall and disaggregated to 16 product categories. Results: Following the introduction of MUP, total household food expenditure in Scotland declined by 1.0%, 95%CI [-1.9%, -0.0%], and total food volume declined by 0.8%, 95%CI [-1.7%, 0.2%] compared to the north of England. There is variation in response between product categories, with less spending on fruit and vegetables and increased spending on crisps and snacks. Conclusion: Minimum unit pricing for alcohol has displaced some household food purchasing and the pattern of changes in food categories appears to be less desirable from a healthy diet perspective. However, changes caused by a minimum price at a nominal 50 pence per unit of alcohol are relatively small.

Effect of different food groups on energy intake within and between individuals.

PURPOSE: Energy intake varies day-to-day because we select different foods, and different amounts of these foods. Energy balance is not tightly regulated over the short-term, and the variability in diet results in an energy surplus or deficit. The aim of this study was to explore how consuming more, or less, than usual amounts of foods contributed towards balancing of total energy intake (TEI) within a day. METHODS: Four-day food records came from 6155 adult participants of the National Diet and Nutrition Survey to study these effects. Within-individual regression models of the energy from 60 food groups on TEI were calculated. Energy intake variation within-individuals was regressed separately on the variation in amounts of each food group. Regression models were also fitted to individual four day means. RESULTS: Within-individual coefficients ranged from about 0 for high-fibre breakfast cereals to 1.7 for sugar preserves and spreads. Three food groups (e.g. low-calorie soft drinks) tended to reduce TEI, and 13 food groups (e.g. margarine and other spreads, and alcoholic drinks) tended to elevate TEI above the energy content of the food group when more than usual amounts were consumed. Foods groups of higher energy densities, or lower fibre content (e.g. typical "snack" foods, low-fibre bread, and processed meat) tended to promote greater TEI more so than did food groups of lower energy densities (e.g. meat, fish, high-fibre foods, and potatoes). CONCLUSION: Different food groups vary considerably in the extent to which they affect TEI in free-living adults. The associations between consuming more, or less, than usual amounts of foods and the effects on TEI are consistent with those found in laboratory studies. Importantly, the present study found similar associations, but using a different methodology and in observational data, providing novel information on energy intake compensation.

Identification of psychological correlates of dietary misreporting under laboratory and free-living environments.

Errors inherent in self-reported measures of energy intake (EI) are substantial and well documented, but correlates of misreporting remain unclear. Therefore, potential predictors of misreporting were examined. In Study One, fifty-nine individuals (BMI = 26·1 (sd 3·8) kg/m2, age = 42·7 (sd 13·6) years, females = 29) completed a 14-d stay in a residential feeding behaviour suite where eating behaviour was continuously monitored. In Study Two, 182 individuals (BMI = 25·7 (sd 3·9) kg/m2, age = 42·4 (sd 12·2) years, females = 96) completed two consecutive days in a residential feeding suite and five consecutive days at home. Misreporting was directly quantified by comparing covertly measured laboratory weighed intakes (LWI) with self-reported EI (weighed dietary record (WDR), 24-h recall, 7-d diet history, FFQ). Personal (age, sex and %body fat) and psychological traits (personality, social desirability, body image, intelligence quotient and eating behaviour) were used as predictors of misreporting. In Study One, those with lower psychoticism (P = 0·009), openness to experience (P = 0·006) and higher agreeableness (P = 0·038) reduced EI on days participants knew EI was being measured to a greater extent than on covert days. Isolated associations existed between personality traits (psychoticism and openness to experience), eating behaviour (emotional eating) and differences between the LWI and self-reported EI, but these were inconsistent between dietary assessment techniques and typically became non-significant after accounting for multiplicity of comparisons. In Study Two, sex was associated with differences between LWI and the WDR (P = 0·009), 24-h recall (P = 0·002) and diet history (P = 0·050) in the laboratory, but not home environment. Personal and psychological correlates of misreporting identified displayed no clear pattern across studies or dietary assessment techniques and had little utility in predicting misreporting.

Self-reported food intake decreases over recording period in the National Diet and Nutrition Survey.

From 2008, the UK's National Diet and Nutrition Survey (NDNS) changed the method of dietary data collection from a 7-d weighed diary to a 4-d unweighed diary, partly to reduce participant burden. This study aimed to test whether self-reported energy intake changed significantly over the 4-d recording period of the NDNS rolling programme. Analyses used data from the NDNS years 1 (2008/2009) to 8 (2015/2016) inclusive, from participants aged 13 years and older. Dietary records from participants who reported unusual amounts of food and drink consumed on one or more days were excluded, leaving 6932 participants. Mean daily energy intake was 7107 kJ (1698 kcal), and there was a significant decrease of 164 kJ (39 kcal) between days 1 and 4 (P < 0·001). There was no significant interaction of sex or low-energy reporter status (estimated from the ratio of reported energy intake:BMR) with the change in reported energy intake. The decrease in reported energy intake on day 4 compared with day 1 was greater (P < 0·019) for adults with higher BMI (>30 kg/m2) than it was for leaner adults. Reported energy intake decreased over the 4-d recording period of the NDNS rolling programme suggesting that participants change their diet more, or report less completely, with successive days of recording their diet. The size of the effect was relatively minor, however.

Healthy and sustainable diets that meet greenhouse gas emission reduction targets and are affordable for different income groups in the UK.

OBJECTIVE: To model dietary changes required to shift the UK population to diets that meet dietary recommendations for health, have lower greenhouse gas emissions (GHGE) and are affordable for different income groups. DESIGN: Linear programming was used to create diets that meet dietary requirements for health and reduced GHGE (57 and 80 % targets) by income quintile, taking account of food budgets and foods currently purchased, thereby keeping dietary change to a minimum.Setting/ParticipantsNutrient composition, GHGE and price data were mapped to 101 food groups in household food purchase data (UK Living Cost and Food Survey (2013), 5144 households). RESULTS: Current diets of all income quintiles had similar total GHGE, but the source of GHGE differed by types of meat and amount of fruit and vegetables. It was possible to create diets with a 57 % reduction in GHGE that met dietary and cost restraints in all income groups. In the optimised diets, the food sources of GHGE differed by income group due to the cost and keeping the level of deviation from current diets to a minimum. Broadly, the changes needed were similar across all groups; reducing animal-based products and increasing plant-based foods but varied by specific foods. CONCLUSIONS: Healthy and lower-GHGE diets could be created in all income quintiles but tailoring changes to income groups to minimise deviation may make dietary changes more achievable. Specific attention must be given to make interventions and policies appropriate for all income groups.

Activity energy expenditure is an independent predictor of energy intake in humans.

BACKGROUND: There is evidence that the energetic demand of metabolically active tissue is associated with day-to-day food intake (EI). However, the extent to which behavioural components of total daily energy expenditure (EE) such as activity energy expenditure (AEE) are also associated with EI is unknown. Therefore, the present study examined the cross-sectional associations between body composition, resting metabolic rate (RMR), AEE and EI. METHODS: Data for 242 individuals (114 males; 128 females; BMI = 25.7 ± 4.9 kg/m2) were collated from the baseline control conditions of five studies employing common measures of body composition (air displacement plethysmography) and RMR (indirect calorimetry). Daily EI (weighed-dietary records) and EE (FLEX heart rate) were measured over 6-7 days, and AEE was calculated as total daily EE minus RMR. RESULTS: Linear regression indicated that RMR (ß = 0.39; P < 0.001), fat mass (ß = -0.26; P < 0.001) and AEE (ß = 0.18; P = 0.002) were independent predictors of mean daily EI, with AEE adding ≈3% of variance to the model after controlling for age, sex and study (F(10, 231) = 18.532, P < 0.001; R2 = 0.445). Path analyses indicated that the effect of FFM on mean daily EI was mediated by RMR (P < 0.05), while direct (ß = 0.19; P < 0.001) and indirect (ß = 0.20; P = 0.001) associations between AEE and mean daily EI were observed. CONCLUSIONS: When physical activity was allowed to vary under free-living conditions, AEE was associated with mean daily EI independently of other biological determinants of EI arising from body composition and RMR. These data suggest that EE per se exerts influence over daily food intake, with both metabolic (RMR) and behavioral (AEE) components of total daily EE potentially influencing EI via their contribution to daily energy requirements.

Biological and psychological mediators of the relationships between fat mass, fat-free mass and energy intake.

BACKGROUND: While recent studies in humans indicate that fat-free mass (FFM) is closely associated with energy intake (EI) when in energy balance, associations between fat mass (FM) and EI are inconsistent. OBJECTIVES: The present study used a cross-sectional design to examine the indirect and direct effects of FFM, FM and resting metabolic rate (RMR) on EI in individuals at or close to energy balance. METHODS: Data for 242 individuals (114 males; 128 females; BMI = 25.7 ± 4.9 kg/m2) were collated from the non-intervention baseline conditions of five studies employing common measures of body composition (air-displacement plethysmography), RMR (indirect calorimetry) and psychometric measures of eating behaviours (Dutch Eating Behaviour Questionnaire). Daily EI (weighed dietary records) and energy expenditure (flex heart rate) were measured for 6-7 days. Sub-analyses were conducted in 71 individuals who had additional measures of body composition (dual-energy X-ray absorptiometry) and fasting glucose, insulin and leptin. RESULTS: After adjusting for age, sex and study, linear regression and mediation analyses indicated that the effect of FFM on EI was mediated by RMR (P < 0.05). FM also independently predicted EI, with path analysis indicating a positive indirect association (mediated by RMR; P < 0.05), and a stronger direct negative association (P < 0.05). Leptin, insulin and insulin resistance failed to predict EI, but cognitive restraint was a determinant of EI and partially mediated the association between FM and EI (P < 0.05). CONCLUSIONS: While the association between FFM and EI was mediated by RMR, FM influenced EI via two separate and opposing pathways; an indirect 'excitatory' effect (again, mediated by RMR), and a stronger direct 'inhibitory' effect. Psychological factors such as cognitive restraint remain robust predictors of EI when considered alongside physiological determinants of EI, and indeed, have the potential to play a mediating role in the overall expression of EI.

Estimating plate-based model food proportions in adults living in Scotland using short dietary assessment questionnaires.

AIM: To determine whether a food frequency questionnaire (FFQ) and a short dietary assessment tool can be used to accurately estimate the Eatwell Guide proportions (a plate-based food model) of diets of adults living in Scotland. METHODS: The cross-sectional study was conducted as a follow up of the 2010 Scottish Health Survey (participants aged 18-65 years old). Proportions of the Eatwell Guide food groups (starchy carbohydrates, fruits and vegetables (F&V), dairy and alternatives, protein foods and oils and spreads) were calculated from the Scottish Health Survey Eating Habits Module (SHeS EHM), Scottish Collaborative Group FFQ (SCG FFQ) and a seven-day estimated food diary (reference method), and compared using the Aitchison method and Wilcoxon Signed-Rank Test. Bland-Altman analyses assessed mean difference and 95% limits of agreement between the methods for each food group. RESULTS: Ninety-six adults were included (mean (SD) age = 51.4 (11.1) years; body mass index = 27.1 (4.9) kg/m2 ; 58% female). The SCG FFQ scored a lower median Aitchison distance (1.47) than the SHeS EHM (1.99) (P < 0.001), showing greater agreement with the reference method (P < 0.001). Bland-Altman plots also showed better agreement for the SCG FFQ than the SHeS EHM. Poorest agreement was for starchy carbohydrates (both methods), protein foods (SHeS EHM) and dairy (SCG FFQ). CONCLUSIONS: The SCG FFQ could be used to estimate Eatwell Guide proportions and monitor compliance to the Eatwell Guide recommendations and could be improved with small changes. The SHeS EHM is less suitable, but additional questions on dairy foods, and oils and spreads would improve its ability to estimate the Eatwell Guide proportions.

"A Lot of People Are Struggling Privately. They Don't Know Where to Go or They're Not Sure of What to Do": Frontline Service Provider Perspectives of the Nature of Household Food Insecurity in Scotland.

This qualitative study explored frontline service providers' perceptions of the nature of food insecurity in Scotland in 2015 to inform national policy and the provision of locally-based support for 'at risk' groups. A country-wide in-depth interview study was undertaken with informants from 25 health, social care, and third sector organisations. The study investigated informants' perspectives associated with how food insecurity was manifesting itself locally, and what was happening at the local level in response to the existence of food insecurity. Data analysis revealed three key themes. First, the multiple faces and factors of food insecurity involving not only increased concern for previously recognised 'at risk of food insecurity' groups, but also similar concern held about newly food insecure groups including working families, young people and women. Secondly, respondents witnessed stoicism and struggle, but also resistance amongst some food insecure individuals to external offers of help. The final theme identified community participation yet pessimism associated with addressing current and future needs of food insecure groups. These findings have important implications for the design and delivery of health and social policy in Scotland and other countries facing similar challenges.

Attitudes towards, and purchasing of, Scottish beef and beef products in Scotland - A short communication.

Attitudes and preferences of the main shopper in households (n = 203) across Scotland towards beef and beef products that were produced in Scotland were assessed by questionnaire. Consumer panel purchase data from the preceding six-months were collected for those households by Kantar Worldpanel. Beef products from Scotland accounted for 39% (by value) of all beef purchases, with an additional 46% from Great Britain and 9% from Ireland. Participants tended to report that being locally produced was an important factor when they bought beef and beef products, although this was not reflected in higher proportions of these products being purchased. Participants who rated local production of higher importance did not buy a higher proportion of beef from Scotland than did participants who rated it as less important (41% and 37% respectively, P = 0.448). Stated preferences for locally produced beef and beef products are not translated into higher amounts purchased.

Is misreporting of dietary intake by weighed food records or 24-hour recalls food specific?

BACKGROUND/OBJECTIVES: Healthy eating advice is informed, in part, by dietary surveys that rely on self-reported data. Misreporting of food intake may distort relationships between diet and health outcomes. This study directly quantified the food groups that were under-reported or over-reported in common dietary assessment techniques. SUBJECTS/METHODS: Food and drink consumption of 59 adults, with ad libitum access to a range of familiar foods, was objectively and covertly measured by investigators, and validated against independent measures of energy balance, while participants were resident in the Human Nutrition Unit of the Rowett Institute. Participants self-reported their diets using weighed dietary records (WDR) and multiple-pass 24-hr recalls over two periods of 3 days using a cross-over design. Foods and drinks were aggregated into 41 food groups. RESULTS: The mean daily weight of food and drinks reported was significantly lower than actually consumed; 3.3 kg (p = 0.004, 95% confidence interval (CI) = 3.07-3.55 kg) and 3.0 kg (p < 0.001, CI = 2.80-3.15 kg) for the WDR and 24-hr recall respectively, compared with 3.6 kg for the objective measure. Reported intakes were significantly lower than the objective measure for four and eight food groups (WDR and 24 h recall, respectively), and not significantly different for the remaining food groups. CONCLUSIONS: Although under-reporting was greater for some food groups than for others, 'healthy' foods were not over-reported and 'unhealthy' foods were not consistently under-reported. A better understanding of which foods tend to be misreported could lead to improvements in the methods of self-reported dietary intakes.

Assessing national nutrition security: The UK reliance on imports to meet population energy and nutrient recommendations.

Nutrition security describes the adequacy of the food supply to meet not only energy but also macronutrient and micronutrient requirements for the population. The aim of this study was to develop a method to assess trends in national nutrition security and the contribution of imports to nutrition security, using the UK as a case study. Food supply data from FAO food balance sheets and national food composition tables were used to estimate the nutrient content of domestically produced food, imported food and exported food. Nutrition security was defined as the total nutrient supply (domestic production, minus exports, plus imports) to meet population-level nutrient requirements. The results showed that the UK was nutrition secure over the period 1961-2011 for energy, macronutrients and key micronutrients, with the exception of total carbohydrates and fibre, which may be due to the loss of fibre incurred by processing cereals into refined products. The supply of protein exceeded population requirements and could be met with domestic production alone. Even excluding all meat there was sufficient protein for population requirements. The supply of total fat, saturated fat and sugar considerably exceeded the current dietary recommendation. As regards nutrition security in 2010, the UK was reliant on imported foods to meet energy, fibre, total carbohydrate, iron, zinc and vitamin A requirements. This analysis demonstrates the importance of including nutrients other than energy to determine the adequacy of the food supply. The methodology also provides an alternative perspective on food security and self-sufficiency by assessing the dependency on imports to meet population level nutritional requirements.

What can Secondary Data Tell Us about Household Food Insecurity in a High-Income Country Context?

In the absence of routinely collected household food insecurity data, this study investigated what could be determined about the nature and prevalence of household food insecurity in Scotland from secondary data. Secondary analysis of the Living Costs and Food Survey (2007⁻2012) was conducted to calculate weekly food expenditure and its ratio to equivalised income for households below average income (HBAI) and above average income (non-HBAI). Diet Quality Index (DQI) scores were calculated for this survey and the Scottish Health Survey (SHeS, 2008 and 2012). Secondary data provided a partial picture of food insecurity prevalence in Scotland, and a limited picture of differences in diet quality. In 2012, HBAI spent significantly less in absolute terms per week on food and non-alcoholic drinks (£53.85) compared to non-HBAI (£86.73), but proportionately more of their income (29% and 15% respectively). Poorer households were less likely to achieve recommended fruit and vegetable intakes than were more affluent households. The mean DQI score (SHeS data) of HBAI fell between 2008 and 2012, and was significantly lower than the mean score for non-HBAI in 2012. Secondary data are insufficient to generate the robust and comprehensive picture needed to monitor the incidence and prevalence of food insecurity in Scotland.

Buying less and wasting less food. Changes in household food energy purchases, energy intakes and energy density between 2007 and 2012 with and without adjustment for food waste.

OBJECTIVE: Consumers in the UK responded to the rapid increases in food prices between 2007 and 2009 partly by reducing the amount of food energy bought. Household food and drink waste has also decreased since 2007. The present study explored the combined effects of reductions in food purchases and waste on estimated food energy intakes and dietary energy density. DESIGN: The amount of food energy purchased per adult equivalent was calculated from Kantar Worldpanel household food and drink purchase data for 2007 and 2012. Food energy intakes were estimated by adjusting purchase data for food and drink waste, using waste factors specific to the two years and scaled for household size. SETTING: Scotland. SUBJECTS: Households in Scotland (n 2657 in 2007; n 2841 in 2012). RESULTS: The amount of food energy purchased decreased between 2007 and 2012, from 8·6 to 8·2 MJ/adult equivalent per d (P<0·001). After accounting for the decrease in food waste, estimated food energy intake was not significantly different (7·3 and 7·2 MJ/adult equivalent per d for 2007 and 2012, respectively; P=0·186). Energy density of foods purchased increased slightly from 700 to 706 kJ/100 g (P=0·010). CONCLUSIONS: While consumers in Scotland reduced the amount of food energy that they purchased between 2007 and 2012, this was balanced by reductions in household food and drink waste over the same time, resulting in no significant change in net estimated energy intake of foods brought into the home.

Differences in expenditure and amounts of fresh foods, fruits and vegetables, and fish purchased in urban and rural Scotland.

OBJECTIVE: To quantitatively analyse expenditure on all fresh foods, fruits and vegetables (F&V) and fish across urban and rural households in Scotland. Fresh foods were chosen since, in general, they are perceived to contribute more to health than processed foods. DESIGN: Descriptive analysis of purchase data of all foods brought into the home during 2012 from the Kantar Worldpanel database. Purchase data were restricted to fresh, unprocessed and raw foods or 'fresh to frozen' foods where freezing was part of harvesting. Total household purchases were adjusted for household size and composition. SETTING: Scotland. SUBJECTS: Households (n 2576). RESULTS: Rural households reported the highest expenditure per person on fresh foods and F&V, but also bought the most (kilograms) of these items. There were linear trends of average prices paid with urban-rural location (P<0·001), with average prices paid by large urban and remote rural households being £2·14/kg and £2·04/kg for fresh foods, £1·64/kg and £1·60/kg for F&V and £10·07/kg and £10·20/kg for fish, respectively, although differences were quantitatively small. CONCLUSIONS: Contrary to previous studies, purchase data show that access to and average prices of fresh foods generally, and F&V and fish specifically, are broadly similar between urban and rural areas. Therefore, the higher expenditure on these foods in rural v. urban areas is probably due to factors other than pricing and availability.

Assessing the relative validity of the Scottish Collaborative Group FFQ for measuring dietary intake in adults.

OBJECTIVE: To assess the relative validity of the latest version of the Scottish Collaborative Group (SCG) FFQ (version 6.6) in adults living in Scotland. DESIGN: A cross-sectional validation study. Participants completed the self-administered, 169-item SCG FFQ followed by a 7 d, non-weighed food diary. Energy and energy-adjusted macronutrients and micronutrients were examined for relative validity through Spearman's correlation, the percentage of classification into thirds of intake, Cohen's weighted kappa (κ w) and Bland-Altman analysis. SETTING: General population living in Scotland. SUBJECTS: Ninety-six adults aged 18-65 years. RESULTS: Spearman's correlation coefficients ranged from 0·21 (retinol) to 0·71 (Mg). A median of 52 % of adults were correctly classified into thirds of intake (range: 42 % (PUFA, MUFA and Fe) to 64 % (percentage energy from carbohydrates)) and 8 % were grossly misclassified into opposite thirds of intake (range: 3 % (carbohydrates, percentage energy from carbohydrates) to 19 % (thiamin)). Values of κ w ranged between 0·20 (PUFA, ß-carotene) to 0·55 (percentage energy from carbohydrates). In the Bland-Altman analysis, the smallest limits of agreement, when expressed as a percentage of the mean intake from the FFQ and food diary, were seen for the main macronutrients carbohydrates, fat and protein. CONCLUSIONS: As in the previous validation study more than 10 years ago, the FFQ gave higher estimates of energy and most nutrients than the food diary, but after adjustment for energy intake the FFQ could be used in place of non-weighed food diaries for most macronutrients and many micronutrients in large-scale epidemiological studies.

Achieving dietary recommendations and reducing greenhouse gas emissions: modelling diets to minimise the change from current intakes.

BACKGROUND: Average population dietary intakes do not reflect the wide diversity of dietary patterns across the population. It is recognised that most people in the UK do not meet dietary recommendations and have diets with a high environmental impact, but changing dietary habits has proved very difficult. The purpose of this study was to investigate the diversity in dietary changes needed to achieve a healthy diet and a healthy diet with lower greenhouse gas emissions (GHGE) (referred to as a sustainable diet) by taking into account each individual's current diet and then minimising the changes they need to make. METHODS: Linear programming was used to construct two new diets for each adult in the UK National Diet and Nutrition Survey (n = 1491) by minimising the changes to their current intake. Stepwise changes were applied until (i) dietary recommendations were achieved and (ii) dietary recommendations and a GHGE target were met. First, gradual changes (≤50%) were made to the amount of any foods currently eaten. Second, new foods were added to the diet. Third, greater reductions (≤75%) were made to the amount of any food currently eaten and finally, foods were removed from the diet. RESULTS: One person out of 1491 in the sample met all the dietary requirements based on their reported dietary intake. Only 7.5 and 4.6 % of people achieved a healthy diet and a sustainable diet, respectively, by changing the amount of any food they currently ate by up to 50 %. The majority required changes to the amount of each food eaten plus the addition of new foods. Fewer than 5 % had to remove foods they ate to meet recommendations. Sodium proved the most difficult nutrient recommendation to meet. The healthy diets and sustainable diets produced a 15 and 27 % reduction in greenhouse gas emissions respectively. CONCLUSIONS: Since healthy diets alone do not produce substantial reductions in greenhouse gas emissions, dietary guidelines need to include recommendations for environmental sustainability. Minimising the shift from current dietary intakes is likely to make dietary change more realistic and achievable.

Measuring the difference between actual and reported food intakes in the context of energy balance under laboratory conditions.

To date, no study has directly and simultaneously measured the discrepancy between what people actually eat and what they report eating under observation in the context of energy balance (EB). The present study aimed to objectively measure the 'extent' and 'nature' of misreporting of dietary intakes under conditions in which EB and feeding behaviour were continuously monitored. For this purpose, a total of fifty-nine adults were recruited for 12 d, involving two 3 d overt phases and two 3 d covert phases of food intake measurement in a randomised cross-over design. Subjects had ad libitum access to a variety of familiar foods. Food intake was covertly measured using a feeding behaviour suite to establish actual energy and nutrient intakes. During the overt phases, subjects were instructed to self-report food intake using widely accepted methods. Misreporting comprised two separate and synchronous phenomena. Subjects decreased energy intake (EI) when asked to record their food intake (observation effect). The effect was significant in women ( - 8 %, P< 0·001) but not in men ( - 3 %, P< 0·277). The reported EI was 5 to 21 % lower (reporting effect) than the actual intake, depending on the reporting method used. Semi-quantitative techniques gave larger discrepancies. These discrepancies were identical in men and women and non-macronutrient specific. The 'observation' and 'reporting' effects combined to constitute total misreporting, which ranged from 10 to 25 %, depending on the intake measurement assessed. When studied in a laboratory environment and EB was closely monitored, subjects under-reported their food intake and decreased the actual intake when they were aware that their intake was being monitored.

Service evaluation of weight outcomes as a function of initial BMI in 34,271 adults referred to a primary care/commercial weight management partnership scheme.

BACKGROUND: It is not clear if behaviour change programmes are more or less effective for weight management in people with high BMIs than for those who are moderately overweight. An earlier service evaluation reported on the rate and extent of weight loss in a primary care/commercial weight management organisation partnership scheme, in 34,271 patients were referred by their health care professionals to a UK commercial weight management organisation, Slimming World for 12 weekly sessions. This project updated that service evaluation by examining weight loss outcomes as a function of initial BMI in the same 34,271 patients. FINDINGS: Patients referred to the scheme (n = 34,271) were categorised by BMI groups <30 kg/m(2), 30-34.9 kg/m(2), 35-39.9 kg/m(2) and to ≥ 40 kg/m(2). Mean weight losses after 12 weekly sessions were 2.9, 3.6, 4.1, and 4.8 kg for each BMI category respectively. Regression analysis showed that after adjusting for age and gender, relative to the <30 kg/m(2) group, absolute weight losses were 0.8, 1.4 and 2.4 kg more for the 30-34.9 kg/m(2), 35-39.9 kg/m(2) and to ≥ 40 kg/m(2) groups, respectively (all p<0.001). Percent weight loss was similar in each BMI category: 3.7%, 4.0%, 4.0% and 3.9%, respectively (p<0.001). CONCLUSIONS: This service evaluation demonstrates that 12 week referral to a commercial organisation is as effective for people with high BMIs as for those who are moderately overweight.