The analysis of food using a perspective centred on nutrients seems inadequate for understanding the dietary transition and its impact on the growth of obesity and chronic diseases. Industrial food processing is now proposed as the key to explain the relationship between food and health. The NOVA food classification considers the degree and the purpose of food processing, which includes physical, biological and chemical processes used after foods are separated from nature, and before being consumed or prepared as dishes and meals. NOVA has four food groups: (1) unprocessed and minimally processed foods; (2) processed culinary ingredients; (3) processed foods and (4) ultra-processed foods, which are formulations made mostly or entirely from substances derived from group 1 foods and additives, with little if any intact group 1 food. Many investigations linking high ultra-processed food consumption with deterioration of diets and adverse health outcomes are reinforced by prospective studies, systematic reviews and meta-analyses. There are various plausible explanations of why diets high in ultra-processed foods are harmful. Their production and consumption continue to rise worldwide. Efficient and effective public policies and actions that reduce production and consumption of ultra-processed products are needed, to protect human health now and in future.

This review presents evidence related to the postprandial responses after consumption of dairy products focusing on the effect of the dairy matrix and lipid response, which was also presented as part of a speech at the Nutrition Society Winter Conference, January 2023. The key findings are that the dairy product(s) that differentiate from others in the postprandial TAG response are products with a semi-solid structure. There were no differences in lipid responses between cheese and butter. The main factors viscosity, fat globule size and milk fat globule membrane do not seem to explain the effect of the dairy matrix in the acute postprandial response. In summary, it is very difficult to investigate the effects of the dairy matrix per see and with the few studies conducted to date, no clear cause and effect can be established. Future research should focus on the semi-solid dairy matrix, and studies investigating specifically the yoghurt matrix are warranted.

A diet low in fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) improves functional bowel symptoms and is a second-line dietary management strategy for the treatment of irritable bowel syndrome (IBS). The diet is complex and involves three stages: restriction, reintroduction and personalisation and clinical effectiveness is achieved with dietitian-led education; however, this is not always available. The aim of this review is to provide an update on the evidence for using the low FODMAP diet, with a focus on the impact of FODMAP restriction and reintroduction considering long-term management of IBS in a clinical setting. Randomised controlled trials have assessed symptom response, quality of life, dietary intake and changes to the gut microbiota during FODMAP restriction. Systematic reviews and meta-analyses consistently report that FODMAP restriction has a better symptom response compared with control diets and a network analysis reports the low FODMAP diet is superior to other dietary treatments for IBS. Research focused on FODMAP reintroduction and personalisation is limited and of lower quality, however common dietary triggers include wheat, onion, garlic, pulses and milk. Dietitian-led delivery of the low FODMAP diet is not always available and alternative education delivery methods, e.g. webinars, apps and leaflets, are available but remove the personalised approach and may be less acceptable to patients and may introduce safety concerns in terms of nutritional adequacy. Predicting response to the low FODMAP diet using symptom severity or a biomarker is of great interest. More evidence on less restrictive approaches and non-dietitian-led education delivery methods are needed.

The aim of the paper is to review the current evidence on the impact of ‘the timing of energy intake’ on the risk of developing obesity and obesity-related metabolic diseases. The prevalence of obesity is currently increasing worldwide thus becoming a severe health burden for most countries. Indeed, obesity represents a risk factor for several non-communicable diseases such as cancer, type 2 diabetes, dyslipidaemia, CVD and overall mortality. In order to treat obesity, several pharmacological approaches have been developed and are indicated for subjects with obesity with a BMI ≥ 30 kg/m2 or ≥ 27 kg/m2 and obesity-related comorbidities. For severe obesity (BMI ≥ 40 kg/m2), bariatric surgery represents a promising approach. The most common bariatric surgical procedures are represented by the Roux-en-Y gastric bypass, laparoscopic adjustable band, laparoscopic gastric sleeve and biliopancreatic diversion with duodenal switch. Both anti-obesity pharmacological and surgical treatments require change in lifestyle. When a nutritional plan is established, attention is usually paid to macronutrient composition and energy intake, while ‘the time of food’ is not taken into account. Chronotype, which is the attitude of a subject to carry out most of their daily activities in the first (morning chronotype) or second half (evening chronotype) of the day, has been reported to have a role in the pathogenesis of obesity and obesity-related cardiometabolic diseases as well as eating speed. Thus, adopting a physiological timing of energy intake could be an additional strategy to potentiate the current anti-obesity approaches.

The high levels of non-communicable diseases such as CVD and type 2 diabetes mellitus are linked to obesity and poor diet. This continuing emphasis on health in relation to food is proving a powerful driver for the development of cheap but palatable and more functional foods. However, the efficacy of such foods is often hard to prove in human subjects. Thus, a suite of tools has been developed including in silico and in vitro simulations and animal models. Although animal models offer physiologically relevant platforms for research, their use for experimentation is problematic for consumers. Thus, in vitro methods such as Infogest protocols have been developed to provide digestion endpoints or even an indication of the kinetics of digestion. These protocols have been validated for a range of food systems but they still miss the final absorption step. This review discusses the use of such in vitro models and what further steps need to be included to make the bioaccessibility determination more relevant to bioavailability and human health.

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.