School-based programmes can cut teens’ junk food intake by 1,000 calories a day: Study

A new Indian study has found that school-based behavioural programmes can significantly curb junk food consumption among adolescents, cutting daily intake of UPFs (ultra-processed foods) by more than 1,000 calories, offering a promising tool to combat rising childhood obesity and lifestyle diseases.

The research, led by scientists from the PGIMER (Post Graduate Institute of Medical Education and Research), Chandigarh, shows that structured nutrition and behaviour-change interventions in schools can sharply reduce students’ reliance on foods high in salt, sugar and unhealthy fats.

The findings come amid growing concern over increasing rates of obesity, diabetes and heart disease risk among Indian children and teenagers, driven in large part by the widespread availability of fast food, sugary drinks and packaged snacks.

“This study demonstrates the potential of school-based behavioural interventions to reduce ultra-processed food consumption among Indian adolescents, addressing a critical gap in public health practice in low- and middle-income countries,” the researchers said in the paper published in BMJ Global Health. The study also involved experts from Imperial College London and the Public Health Foundation of India.

How the study was conducted

The researchers carried out a cluster-randomised controlled trial across 12 government schools in Chandigarh, focusing on students of Class 8 and involving their parents.

Over a six-month period:

• Adolescents attended 11 structured sessions on nutrition awareness, food choices and behaviour change.

• Parents were given one focused educational session to encourage healthier food environments at home.

• Dietary patterns were assessed using two non-consecutive 24-hour food recalls at the beginning and end of the intervention.

The results showed a sharp and consistent decline in junk food consumption among participating students.

Key findings

Students who underwent the programme consumed:

• Over 1,000 fewer calories per day from ultra-processed foods such as packaged snacks, sugary beverages and fast food.

• Around 270 fewer calories per day from other processed foods, indicating a broader shift away from unhealthy diets.

While the reduction in junk food was significant, the researchers noted that students did not show a comparable increase in fruit intake or home-cooked meals.

“This suggests that reducing unhealthy consumption is easier than building healthy eating habits, and both require different strategies,” the study said.

Schools emerge as critical intervention points

Interestingly, the study found that even with parental involvement, adult eating patterns showed little change, highlighting the unique influence of schools on adolescent behaviour.

The researchers said this underscores the role schools can play as frontline institutions in preventing lifestyle-related diseases such as diabetes, hypertension and obesity.

“Low-cost, scalable education and behaviour-change strategies in schools could have a long-term impact on public health,” the team said, adding that such programmes are particularly relevant for countries like India, where healthcare systems face increasing pressure from non-communicable diseases.

Public health implications

Health experts have long warned that high consumption of ultra-processed foods in adolescence is linked to a greater risk of:

• Type 2 diabetes

• Hypertension

• Obesity

• Certain cancers later in life

The study adds to growing evidence that early, school-based interventions can shift dietary habits before unhealthy patterns become entrenched.

With India witnessing a steady rise in childhood obesity and diet-related illnesses, the findings provide policymakers and education authorities with a practical model to integrate nutrition awareness into school curricula.

The researchers called for wider adoption of such programmes, saying schools offer an effective, low-cost platform to influence millions of children at a formative stage of life — potentially altering the country’s long-term health trajectory.