Researchers in Ireland analyzed data from the UK National Diet and Nutrition Survey (NDNS) to compare dietary habits at two time points: 2008–2012 (Years 1–4) and 2016–2019 (Years 9–11). The study included 4,386 adults aged 18–65 years from nationally representative samples.
“The findings provide scope for policy interventions to increase fiber intake and reduce sugar consumption, particularly among overweight/obese individuals,” the researchers wrote in The British Journal of Nutrition.
“Monitoring trends through nationally representative surveys remains critical to inform targeted health promotion campaigns and support healthier dietary patterns.”
Trends in carbs, fat, protein and fiber
Over recent decades, diets in many populations have shown shifts in carbohydrate, sugar, fat, protein, and fiber intake, often alongside increased consumption of processed foods.
In the UK, public health guidance such as the Eatwell Guide encourages balanced nutrient intake, including higher fiber, lower free sugars, and controlled fat intake. However, many adults still fail to meet these recommendations, particularly for fiber.
However, there is limited up-to-date evidence on how macronutrient intake (carbohydrate, sugar, fat, protein, and fiber) has changed among UK adults in recent years, and how these changes relate to portion sizes and food choices. To address this gap, researchers set out to examine how nutrient intake and dietary composition have changed over a 10-year period.
Shifting macros in the UK diet
Participants completed a four-day food diary, recording everything they ate and drank, including portion sizes, brand names, and preparation methods. Interviewers reviewed each diary to improve accuracy, and researchers then used specialized nutrition software to calculate daily energy and nutrient intake.
The researchers grouped individual foods into 24 core food categories and compared portion sizes, eating frequency, energy intake and macronutrient intake between the two survey periods. They also measured height, weight, waist circumference, and waist-to-hip ratio to assess body weight and body fat distribution.
They then used statistical tests to compare dietary changes over time and examine links between portion size, nutrient intake, and measures of body weight, while adjusting for factors such as age, sex and misreporting.
Results showed that carbohydrate intake decreased by about 60%, but people still consumed more carbohydrates than recommended. Total sugar and free sugar intake also fell, showing some improvement. However, adults continued to eat more sugar than recommended, mainly because many processed foods still contain high amounts of added sugar, the researchers noted.
Fat intake increased by around 19%, but it remained within recommended dietary guidelines, while protein intake increased by about 20.5% and exceeded recommended levels (around 0.75 g per kg of body weight per day).
The researchers suggest this may reflect changing lifestyles, greater demand for convenient high-protein foods, increased awareness of protein for health and fitness, and the growing availability of plant-based protein alternatives.
Part of the growing protein trends across the UK have been attributed to increased intake of appetite suppressing GLP-1 medication. As consuming fewer calories can unintentionally lower protein intake, growing concerns about losing lean muscle mass have led consumers to prioritize protein-rich foods.
Fiber intake on the rise
The research also found that UK adults increased their fiber intake by around 1 g per day over the decade, rising from 17.4 g to 18.4 g per day, which the researchers noted may be due to growing interest in plant-based and vegan diets; however, they still fell well short of the recommended daily intake of 30 g.
Dietary fiber supports digestive health, healthy gut bacteria and regular bowel function, and growing evidence also suggests it can support mental wellbeing, improve sleep quality, and promote healthy ageing.
Fiber intake is increasing thanks to social media-driven trends like “fibermaxxing”, and consumers are becoming savvy in seeking specific types of fiber, such as prebiotics (e.g., galacto-oligosaccharides), that offer science-backed benefits for the gut–brain and gut–muscle axes.
Retailers like Holland & Barrett have said that fiber-related products are seeing strong momentum, particularly in non-traditional formats like functional drinks and “on-the-go” stick packs favored by Gen Z .
Despite growing interest, a significant deficiency remains. Federica Amati, head nutritionist at Zoe, recently told NI that “while most people get plenty of protein, 96% of UK adults are deficient in fiber— it is the country’s number one deficiency” .
Journal: The British Journal of Nutrition; doi: 10.1017/S000711452610782X; “Changes in food patterns over a 10-year period in the UK adult population; findings from the National Diet and Nutrition Survey.” Authors: Papagiannaki, M. et al.
