Developing food-based dietary recommendations in the UK

The present paper provides an overview of the approach to developing food-based dietary recommendations in the UK. UK dietary recommendations are based on independent advice from the Scientific Advisory Committee on Nutrition (SACN). SACN's remit includes specific reference to the nutrient content of individual foods and advice on diet as a whole, including the definition of a balanced diet. SACN's approach is set out in its Framework for Evaluating Evidence and its assessments are supported by the data provided by the National Diet and Nutrition Survey. SACN's risk assessments have primarily focused on energy requirements, macro and micronutrients and/or the needs of specific population groups. However, dietary patterns or individual foods and health outcomes have been considered where sufficient evidence is available. An example of this is SACN's risk assessment on carbohydrates and health, which included consideration of evidence on sugar-sweetened beverages and the resulting dietary recommendations on free sugars and sugar-sweetened beverages led to a range of policies to reduce sugar intake in the UK, including the soft drinks industry levy. SACN has also recently published a position statement on processed foods and health. Government dietary advice is encapsulated in the UK's national food model, the Eatwell Guide. The Eatwell Guide shows the proportions in which different food groups should be consumed to have a well-balanced, healthier, more sustainable diet, to help meet nutrient requirements and reduce the risk of chronic disease. Any substantive change to government dietary advice is likely to lead to a review of the national food model.

Prevalence of neural tube defects in England prior to the mandatory fortification of non-wholemeal wheat flour with folic acid: a population-based cohort study

OBJECTIVES

To determine the baseline trends in the total birth prevalence of neural tube defects (NTDs) in England (2000-2019) to enable the impact of folic acid fortification of non-wholemeal wheat flour to be monitored.

DESIGN

Population-based, observational study using congenital anomaly (CA) registration data for England curated by the National Congenital Anomaly and Rare Disease Registration Service (NCARDRS).

SETTING

Regions of England with active registration in the time period.

PARTICIPANTS

Babies that were liveborn or stillborn and pregnancies that resulted in a termination of pregnancy or a late miscarriage (20-23 weeks' gestation) with an NTD.

MAIN OUTCOME MEASURES

Total birth prevalence of anencephaly, spina bifida and all NTDs in England. Poisson regression analysis was used to evaluate time trends with regional register as a random effect. The progress of national registration across England was assessed.

RESULTS

There were 4541 NTD pregnancies out of 3 637 842 births in England; 1982 anencephaly and 2127 spina bifida. NTD prevalence was 12.5 (95% CI 12.1 to 12.9) per 10 000 total births. NTD prevalence per 10 000 total births was significantly higher in 2015-2019 (13.6, 95% CI 12.9 to 14.4) compared with 2010-2014 (12.1, 95% CI 11.7 to 12.5). An increasing trend in NTDs overall was detected (incidence rate ratio (IRR) 1.01, 1.00 to 1.02), although further analysis determined this effect was confined to 2015-2019 (compared against 2000-2004, IRR 1.14, 1.04 to 1.24). The birth prevalence of anencephaly reflected this pattern. The prevalence of spina bifida remained relatively stable over time.

CONCLUSIONS

Baseline NTD prevalence for England has been established. National and standardised CA registration is in place, facilitating the systematic and consistent monitoring of pre-fortification and post-fortification NTD trends and evaluating the impact of fortification on NTD prevalence.

Shedding and seroprevalence of pathogenic Leptospira spp. in sheep and cattle at a New Zealand Abattoir

A cross-sectional study was carried out on sheep and cattle slaughtered at a New Zealand abattoir from September to November 2010 to investigate the supplier-specific shedding rate, renal carriage rate and seroprevalence of leptospires. In the 2008/2009 season, this abattoir experienced three human leptospirosis cases from 20 staff, of which two were hospitalized. Urine, kidney and blood samples were collected from carcasses of 399 sheep (six suppliers, 17 slaughter lines) and 146 cattle (three suppliers, 22 slaughter lines). The urine and kidney samples were tested by quantitative real-time PCR (qPCR), while serum samples (from coagulated blood samples) were tested by microscopic agglutination test (MAT). In total, 27% (73/274; 95% CI: 18-37) of urine samples tested positive by qPCR. Species-specific shedding rates (prevalence of positive urine qPCR) were 31% (95% CI: 17-48) for sheep and 21% (95% CI: 14-30) for cattle. For 545 kidney samples tested, 145 were qPCR positive (27%; 95% CI: 17-39). The average prevalence of kidney qPCR positivity was 29% (95% CI: 17-45) for sheep and 21% (95% CI: 15-28) for cattle. Three hundred and thirty of 542 sampled sheep and cattle had antibodies against Leptospira borgpetersenii serovar Hardjobovis (Hardjobovis) and/or Leptospira interrogans serovar Pomona (Pomona), based on reciprocal MAT titre ≥1 : 48 (overall seroprevalence of 61%; 95% CI: 48-73). Seroprevalence was 57% (95% CI: 40-72) for sheep and 73% (95% CI: 59-83) for cattle. Among the seropositive animals, 41% (70/170; 95% CI: 30-54) were shedding (tested positive by urine qPCR) and 42% (137/330; 95% CI: 30-54) had renal carriage (tested positive by kidney qPCR). Some risk management options for abattoirs or farms to prevent human leptospirosis infections include vaccination of maintenance hosts, the use of personal protective equipment, and the application of urine qPCR to detect shedding status of stock as surveillance and as an alert.

Dietary restraint and the mis-reporting of anthropometric measures by middle-aged adults

OBJECTIVE

To assess whether levels of dietary restraint are associated with mis-reporting measures of adiposity by middle-aged adults.

DESIGN

Cross-sectional study of middle-aged men and women, the parents of a group of young adults followed up since birth.

METHODS

In all, 631 couples were mailed questionnaires and asked to record their height, weight and waist circumference. A paper tape measure with instructions for use was attached. Couples also completed the dietary restraint section of the Dutch Eating Behaviour Questionnaire, and provided information on employment and lifestyle habits. A subsample of participants was then invited to attend a clinic where detailed anthropometric measures were taken.

RESULTS

In all, 435 women (69%) and 332 men (55%) completed the questionnaire; of those invited, 182 (85%) women and 102 (61%) men attended a clinic session. Regression analyses showed that the dietary restraint score was associated with the mis-reporting of BMI by women (P<0.01), but not men (test for interaction with gender, P=0.11). In women, the difference between the measured and reported BMI increased by 0.36 kg/m(2) (0.11-0.61) per unit increase in restraint score. This association was independent of age, smoking, social class, slimming, exercise frequency or television viewing time, but was attenuated in models controlling for measured BMI. The dietary restraint score was not associated with mis-reporting of waist circumference in men or women.

CONCLUSIONS

Dietary restraint score may be a useful tool for identifying individuals more likely to mis-report anthropometric measurements, although associations may vary by gender.