New research has found that having a lower body mass index (BMI) is consistently linked with having a lower risk of type 2 diabetes risk, even among those with genetic risk factors for the condition.
Carried out by researchers at Stanford University, USA, and the University of Oxford, UK, the new study looked at data gathered from 287,394 people between the ages of 40 and 69 participating in UK Biobank, a large long-term study which includes genomic data on more than half a million UK residents.
The researchers used the data to look at the association between BMI, a family history of diabetes and genetic risk factors affecting the risk of type 2 diabetes.
The findings, published online in PLOS Medicine, showed that a higher risk of diabetes was associated with a higher BMI, a family history of type 2 disease and genetic risk factors.
The team also found that a lower BMI was consistently associated with a reduced risk of diabetes, regardless of BMI, family history and genetic risk categories, suggesting that all individuals could potentially reduce their diabetes risk through weight loss. They predicted that weight loss would substantially reduce diabetes risk even among lower-risk individuals, for example, a 1-kg/m2 BMI reduction was associated with a 1.37-fold reduction in diabetes risk among non-overweight individuals (those with a BMI of less than 25 kg/m2) and without a family history of diabetes, an effect similar to that of reducing BMI among obese individuals with a family history.
Although weight loss has already been found to reduce the risk of type 2 diabetes in high-risk and pre-diabetic individuals, its effect in those with a lower risk of the condition has not been well-studied.
"These findings suggest that all individuals can substantially reduce their type II diabetes risk through weight loss," commented the authors, although they also noted that caution must be applied when interpreting the results, as they didn't actually look at weight loss interventions in this study. They also added that although the new analysis "can determine that lower lifetime BMI is protective against diabetes, that does not necessarily imply weight loss later in life, after carrying excess weight for decades, would have the same result."