The long-running Whitehall II study included 2,521 adults ages 39 to 62 (75% men), among whom 66 with 20 year follow-up had a body mass index 0f 30 kg/m2 or more but were considered metabolically healthy.
That group, representing 37% of all 181 obese people in the study, had no more than one of the following:
- HDL cholesterol level less than 1.03 mmol/L for men or 1.29 mmol/L for women
- Blood pressure of at least 130/85 mmHg or use of antihypertensive medication
- Fasting plasma glucose of at least 5.6 mmol/L or use of anti-diabetic medication
- Triglyceride level at least 1.7 mmol/L
- Insulin resistance as indicated by a homeostatic model assessment of insulin resistance greater than 2.87 (baseline 90th percentile value)
Only about one in 10 of this group lost enough weight over the 20-year follow-up to move into the healthy nonobese category.