Malnutrition is common among older adults in health-care settings and is associated with decreased quality of life (QoL). The present study aimed to investigate the effect on health-related QoL (HRQoL) among older adults after 6 months of treatment with individual dietary advice (DA) and/or oral nutritional supplements (ONS), utilising 409 patients included in a multicentre randomised controlled trial of patients ≥ 65 years old, stratified according to nutrition status (malnourished/at risk of malnutrition), admitted to hospital in Sweden 2010–2014. Patients were randomised into four arms: DA, ONS, DA + ONS or routine care (control). The intervention started at discharge from hospital, with HRQoL measured using European QoL five-dimension, three-level (EQ-5D-3L) and European QoL-visual analogue scale (EQ-VAS) at baseline and at 6-month, 1-year and 3-year follow-ups. Data were analysed using the Kruskal–Wallis test and multiple linear regression. Overall, HRQoL increased from baseline to follow-ups, although the magnitude of change in EQ-5D-3L did not differ significantly between the four arms in any of the nutrition groups. However, a significant difference was observed for change in EQ-VAS from baseline to 6-month follow-up in the malnourished group, with mean changes of 22·4 and –3·4 points for the ONS and control groups, respectively (P = 0·009). In the multiple linear regression analyses, participants in the ONS arm had 27·5, 34·4 and 38·8 points larger increases in EQ-VAS from baseline to the 6-month (P = 0·011), 1-year (P = 0·007) and 3-year (P = 0·032), respectively, follow-ups than the control group. The use of ONS improved subjectively assessed HRQoL in these malnourished older adults.

The efficacy by which dietary interventions influence risk markers of multi-factorial diseases is mainly determined by taking population-based approaches. However, there exists considerable inter-individual variation in response to dietary interventions, and some interventions may benefit certain individuals or population subgroups more than others. This review evaluates the application of nutrigenomic technologies to further the concept of personalised nutrition, as well as the process to take personalised nutrition to the marketplace. The modulation of an individual's response is influenced by both genetic and environmental factors. Many nutrigenetics studies have attempted to explain variability in responses based on a single or a few genotypes so that a genotype may be used to define personalised dietary advice. It has, however, proven very challenging to define an individual's responsiveness to complex diets based on common genetic variations. In addition, there is a limited understanding of what constitutes an optimal response because we lack key health biomarkers and signatures. In conclusion, advances in nutrigenomics will undoubtedly further the understanding of the complex interplay between genotype, phenotype and environment, which are required to enhance the development of personalised nutrition in the future. At the same time, however, issues relating to consumer acceptance, privacy protection as well as marketing and distribution of personalised products need to be addressed before personalised nutrition can become commercially viable.

The present paper explores the level of evidence required to justify giving dietary advice to the public. There are important practical differences between the development of public health nutrition guidelines and guidelines for clinical practice. While the gold standard for evidence for clinical practice guidelines is a meta-analysis of a number of randomised controlled trials, this is often unrealistic and sometimes unethical for the evaluation of public health nutrition interventions. Hence, epidemiological studies make up the bulk of evidence for nutrition guidelines. Tea and coffee are an interesting case study in relation to this issue. They are two of the most commonly consumed beverages worldwide, yet there is little dietary advice on their use. The evidence for a relationship between coffee or tea consumption and several diseases is discussed. The available studies, predominantly epidemiological, together with animal and in vitro studies, indicate that coffee and tea are both safe beverages. However, tea is the healthier option because it has a possible role in the prevention of several cancers and CVD. While the evidence for such relationships is not strong, the public will continue to drink both tea and coffee, and will continue to ask nutritionists to make recommendations. It is therefore argued that advice should be given on the best available data, as waiting for complete data to become available could have severe consequences for public health.

Current interest in preventive nutritional supplementation strategies during the reproductive cycle in developed countries focuses mainly on iron and folic acid. Iron deficiency is the most common cause of anaemia. Inadequate iron nutrition is mainly a problem in developing countries but it also seems to affect a large proportion of pregnant women in the industrialised world. There is no chance for diet modification alone to meet iron requirements during pregnancy. However, dietary advice must be provided to increase iron intake and iron bioavailability. The best choice is prescribed supplementation adapted to the individual's needs.

Folic Acid supplementation during the periconceptional period reduces the occurrence and recurrence of neural tube defects (NTDs). According to the updated edition of American Dietary Reference Intakes, recommended dietary allowance for folate for women of childbearing age varies throughout the reproductive cycle from 400 μg day−1 of dietary folate equivalents (DFEs) for non-pregnant women, to 600 μg day−1 DFEs for pregnant women and 500 μg day−1 DFEs in lactating women. Increasing dietary folate, fortifying staple foods with folic acid or use of folic acid supplements can increase folate intake.

To assess the effect of an antenatal nutrition programme designed specifically for the local population, questionnaires on nutrition knowledge, attitudes to healthier eating and 4 d diet diaries were completed by women attending routine antenatal clinics. Women who received the nutrition education programme were allocated into an Intervention Education Group whilst those women who did not were allocated into a Routine Education Group. The results showed that knowledge about nutrition was significantly higher in the intervention group. However, no significant differences were detected between the two groups for attitude variables or nutrient intake. It is concluded, therefore, that the most-widely-read form of nutrition advice for pregnant women may have some impact on nutrition knowledge but has little effect on nutrient intake during pregnancy.