BMI insights

Our community is on a mission to lower its BMI and body fat

We know that obesity is related to poor health outcomes. It seems like a simple connection with weight. But actually, weight and fat are not as tightly related as you might think.

BMI Insights

What we've found

These insights are based on correlations which are statistical links between two sets of data. While we focus only on more plausible and interesting links, they should not be seen to imply cause or effect.

We’ve been asking our users about their Body Mass Index (BMI), that’s a measure which uses your height and weight to work out if your weight is healthy. But that doesn’t tell the whole story; you might be a normal weight according to your height, but you can still carry too much body fat. So as well as BMI, we’ve also been asking our users to grab a tape measure and check their waist and hip, which can better indicate potential health problems. Let’s see what the figures for both say.

 

The Evergreen community's BMI

The graph below indicates how the average BMI of our Evergreen community has been changing.

We can’t find this kind of data about people’s BMI recorded over time elsewhere, so we may be the only people collecting this kind of information on this scale and exploring what it might mean. Questions popping up for us include: why does our community’s BMI dip significantly at the end of 2021, and then steadily rise? We’d love to hear if you have any thoughts on this – what do you think might have influenced this shift? If you’d like to share your ideas, please get in touch with us at [email protected] and let us know.

Evergreen Community BMI

BMI and disease

Type 2 diabetes

Using Evergreen Life users’ data* on the incidence of diabetes and BMI, the following graph shows that the likelihood of having a type 2 diabetes diagnosis varies with BMIs in the range 18-45.  

The likelihood of having type 2 diabetes increases with every additional kilogram of weight, even for those at the upper end of the healthy weight range. We’ve also shown the Evergreen Life community’s average BMI for comparison, represented by the black vertical line.

BMI correlates

The following chart compares people in the Evergreen community who have a healthy BMI with those who have a BMI of over 25. It’s well known that those with lower BMIs are less likely to have a type 2 diabetes diagnosis. What’s more surprising is they are likely to report feeling happier.

So does a healthy BMI make you happy, or does being happy help you maintain a healthy BMI? Sadly we can’t answer that yet, our data is only telling us there is a link. However, in time and with our community’s help, we hope to be able to help shed more light on these links.

Factors associated healthy BMI

BMI and age

Looking at the average BMI of our users in different age groups, all averages are still overweight. However as the graph below shows, it seems that of the users who are tracking it, those under 35 years old and 65+ are losing weight while those in the middle age categories are either staying the same or gaining weight.

Watch your waistline

Research shows that a high waist to hip ratio is a better indicator for risk of cardiovascular heart disease, type 2 diabetes and other health problems, than BMI. That’s because if you have more fat stored around your waist, it’s likely that you’ll have fat wrapped in and around your internal organs which can cause health problems.

The table below shows what the World Health Organisation regards as a healthy waist to hip ratio:

And here’s a graph that breaks down the waist to hip ratios of the men (green) and women (pink) in our Evergreen Life community. The green and pink lines represent the cut-off points of a healthy ratio for men and women respectively. It shows that 71.65% of men have an unhealthy waist to hip ratio measurement, compared to only 32.89% of women.

Waist Hip ratio men vs women

It’s important to check your waistline. See the article here on how to measure your body fat and find tips on how to reduce this if you need to.

 

Statistical disclaimers:

*This graph uses data from Evergreen Users who have a linked GP record and a value of their BMI. A locally weighted scatterplot smoothing method is used (see https://bit.ly/3pcmdMd) to generate the curve and its confidence intervals (95% Confidence level). BMI values over 45 and under 18 are truncated due to small sample size in these ranges, resulting in imprecise estimates that are uninformative.

Insights disclaimer: All insights are statistically significant at the 95% confidence level.

Maps disclaimer: The map uses data from Evergreen life users and is the rolling average proportion of users in the regions shown that are overweight, the regions that do not have sufficient data remain white.

BMI disclaimer: The average BMI by age includes data from Evergreen Life users within the ages of 18 and 110 years old. Obese is defined as a BMI > 30 and Overweight is defined as 25< BMI <30 as per https://www.nhs.uk/conditions/obesity/

Waist hip ratio disclaimer: waist hip ratio is calculated from the measurement of Evergreen Life hip measurements and waist measurements.