UK study suggests adolescents' diet quality is neither healthy nor sustainable

New research being presented at this year's European Congress on Obesity (ECO) in Maastricht, Netherlands (4-7 May), suggests secondary school pupils across the West Midlands region of the UK are not eating a healthy, sustainable diet. The study is by Dr. Ankita Gupta and colleagues from the University of Birmingham, UK.

In 2019, The EAT-Lancet Commission called for a broad dietary change that would take into account both human and planetary health to ensure that future food systems can sustainably and nutritiously feed the estimated population of 10 billion people in 2050. The EAT-Lancet planetary health diet stipulates daily intakes of different foods, and consists of a lot of whole grains, vegetables, fruit, nuts, seeds and pulses (peas, beans and lentils), and substantially less meat, sugar and saturated fat compared with current consumption.

"Following the EAT–Lancet reference diet means eating plant-based foods on most days with small amounts of meat and fish. Ultra-processed foods, such as soft drinks, frozen dinners and reconstituted meats and sugars are mostly avoided", explains Gupta.

The benefits of adopting a planetary health diet include reducing deaths and illness from cardiovascular disease, high blood pressure, type 2 diabetes, and cancer, as well as reducing ecological footprints and greenhouse gas production. However, the extent to which adolescents in the UK meet the requirements for a healthy and sustainable diet is unknown.

To find out more, the researchers set out to compare the diets of adolescents who participated in the Birmingham Food provision, cUlture and Environment in secondary schooLs (FUEL) study—that is examining the national School Food Standards and related national policy in secondary schools across the West Midlands—with the EAT-Lancet planetary health diet. They analyzed cross-sectional data from 16 schools including 942 pupils between the ages of 11 and 15 years, collected as part of the FUEL study. Pupils were asked to complete two questionnaires, which were repeated 2-4 weeks later—one collecting demographic data (eg, ethnicity, age, sex, home postcode), and the other asking about the food and drinks they had consumed in the past 24 hours.

Food intake (grams/day) was calculated for the food groups outlined in the EAT-Lancet diet. The researchers then calculated the proportion of pupils meeting each dietary recommendation from the planetary health diet (see table in notes to editors).

The researchers found that average consumption of free sugar (that includes table sugar, the sugar added to food and drinks, and found naturally in fruit juices, syrups and honey), potatoes, red meat (beef, lamb, pork), and chicken and other poultry, exceeded the daily intake recommended by the EAT-Lancet diet.

Almost three-quarters (73%) of pupils consumed more than the daily maximum recommended 31g (about seven teaspoons) of free sugar, and almost a third (31%) ate more than the maximum recommended 58g of chicken and processed poultry (equivalent to four McDonald's chicken nuggets) and potatoes (100g).

In addition, the average intake of fruit, vegetables, dairy, wholegrains, legumes and fish fell below the recommended intake, with 70% of adolescents not consuming the recommended 100g of fruit per day (equivalent to one apple), and over 90% not eating the recommended 200g of vegetables.

"Governments and dietary guidelines need to acknowledge that a third of adolescents in the UK have overweight or obesity, and consider interventions that focus on transforming food systems, changing food policy and supporting diets that benefit both young people's health and the planet", says Gupta. "For many young people living in the UK and other western countries, eating according to the planetary health diet will entail a major change, and it will take time to change our eating habits. Schools are where children spend most of their time, making this a crucial setting for programs, strategies, and policies that alter the food environment by shaping the choices available and the options they choose. We tend to stick to the dietary habits we develop as children."