BCS70

For many people, maintaining a healthy weight is one of the best things we can do to protect our health. But according to findings from BCS70, the benefits of a keeping BMI in a normal range may be more far-reaching.

Previous research has shown that overweight and obesity – particularly in sensitive periods like childhood and adolescence – can lead to the onset of a range of illnesses. Researchers at the Chongqing Medical University in China were interested to know if carrying excess weight earlier in our lives can affect other outcomes in adulthood, like educational attainment.

What we asked you

We have tracked your height and weight throughout your lives, which can be used to calculate body mass index (BMI). The researchers used your measurements at ages 10, 16 and 42 to get a sense of BMI throughout your lives.

When you were 42 years old, we measured your cognitive ability with a vocabulary test. We also recorded the highest educational qualification you had achieved by this age (such as O-levels, A-levels or a university degree), and collected information about your health.

At age 42 we also asked you how often you felt certain ways, such as “I’ve been interested in new things”, “I’ve been feeling confident” and “I’ve been feeling close to other people”.

What the research found

Overall, most of the study members included in this research were at a healthy weight at ages 10, 16 and 42.

At ages 10 and 16, around 1 in 10 were carrying excess weight, and around 1 in 20 were underweight. Around 1 in 14 gained an unhealthy weight between childhood and adolescence, and slightly fewer had achieved a healthy weight at age 16, having been overweight when they were younger. By age 42, over 1 in 5 had a BMI greater than 30 – a standard measure of obesity.

At age 42, those who had been heavier as teenagers performed worse on the vocabulary test and had lower educational qualifications, on average . This was true even when accounting for other influential factors , such as your family’s financial and social circumstances when you were growing up.

Weight at age 10 didn’t appear to be connected to these adult outcomes directly, although most people were in a similar weight range at both ages.

However, neither weight in childhood and adolescence was linked to how you felt at age 42 – there was no significant difference in how often people felt confident, close to other people or interested in trying new things in their early 40s.

Why this research matters

Obesity has been connected to a range of health problems, from diabetes to poor cognitive function. Young people who are an unhealthy weight can be subjected to a range of other social and health problems, including low self-esteem, social discrimination, and ill health – all of which can have lasting effects.

With obesity becoming more and more prevalent around the world, it is extremely important for healthcare and public health professionals to understand the potentially wide-ranging effects, as well as the benefits of maintaining a healthy weight, particularly at critical stages in our lives .

Read the full research report

Early Weight Status and Human Capital in Adulthood: A 32-Year Follow-Up of the 1970 British Cohort Study by Yi Luo and Mimi Xiao was published in the International Journal of Public Health in February 2024.