Normal Weight Obesity and Cardiometabolic Risk Factors

Normal weight obesity (NWO) describes individuals who present with a body mass index within the conventional normal range yet harbour an elevated proportion of body fat. This phenotype has emerged as a critical public health concern owing to its association with a spectrum of cardiometabolic disturbances traditionally linked to overt obesity. Despite an appearance of leanness, those with NWO frequently exhibit central adiposity, low-grade inflammation and dysregulated lipid and glucose metabolism. The disproportionate accumulation of visceral fat in these individuals contributes to endothelial dysfunction, heightened blood pressure and impaired insulin sensitivity. As global efforts to curtail obesity focus on body mass index alone, NWO remains under-recognised in clinical practice. Improved detection through body composition assessment, coupled with tailored lifestyle and dietary interventions, holds promise for mitigating long-term risks of type 2 diabetes, atherosclerosis and cardiovascular morbidity in this concealed at-risk group.

Research from Nature Portfolio

A large cross-sectional study conducted in an urban African population quantified the prevalence of NWO and demonstrated that nearly one in five adults with a normal body mass index exhibited excess body fat. Those individuals had significantly higher diastolic blood pressure, odds of hypertension and elevated blood glucose, alongside unfavourable lipid profiles, compared with their lean counterparts. In a longitudinal investigation of non-diabetic adults, distinct patterns of body mass index trajectory were identified prior to diabetes onset. A substantial subgroup with low initial BMI experienced progressive gains in visceral adiposity and corresponding declines in β-cell compensation for insulin resistance, underlining that fat distribution rather than absolute weight is pivotal in diabetes pathogenesis, even among those who remain within normal weight boundaries.

Normal Weight Obesity and Cardiometabolic Risk Factors publication trend

The graph below shows the total number of articles in normal weight obesity and cardiometabolic risk factors across all publications each year (not limited to Nature Index journals).

Technical terms

Normal Weight Obesity (NWO): Condition characterised by a normal body mass index alongside an elevated body fat percentage.

Body Mass Index (BMI): Ratio of body weight to the square of height, commonly used to categorise underweight, normal weight, overweight and obesity.

Body Fat Percentage (BF%): Proportion of total body mass composed of adipose tissue, assessed through techniques such as bioelectrical impedance or skinfold measurements.

Metabolic Syndrome: Cluster of interrelated risk factors—including raised blood pressure, dyslipidaemia, hyperglycaemia and central adiposity—that collectively elevate cardiovascular and diabetes risk.

Insulin Resistance: Impaired biological response to insulin, leading to reduced glucose uptake and compensatory hyperinsulinaemia.

Dyslipidaemia: Abnormal lipid profile, typically involving elevated triglycerides or low levels of high-density lipoprotein cholesterol.

References

1. Association of normal weight obesity phenotype with inflammatory markers: A systematic review and meta-analysis. Frontiers in Immunology (2023).
2. Association between normal-weight obesity and cardiometabolic risk factors among adults in Addis Ababa, Ethiopia. Scientific Reports (2023).
3. Body mass index trajectory patterns and changes in visceral fat and glucose metabolism before the onset of type 2 diabetes. Scientific Reports (2017).
4. Prevalence of normal weight obesity and its associated cardio-metabolic risk factors – Results from the baseline data of the Kerala Diabetes Prevention Program (KDPP). PLOS ONE (2020).
5. Normal Weight Obesity and Cardiometabolic Risk Factors: A Systematic Review and Meta-Analysis. Frontiers in Endocrinology (2022).