Endocrine Abstracts

Obesity is often framed as a consequence of inadequate physical activity, and patients with severe obesity sometimes attribute their weight gain to immobility and reduced exercise. We sought to compare Total Daily Energy Expenditure (TDEE) in adults with severe obesity to what their predicted TDEE would be at their Ideal Body Weight (IBW). We conducted a cross-sectional analysis of the Croí CLANN prospective cohort study of patients with severe obesity attending our regional bariatric service. Data on weight, height, age and sex were used to estimate Basal Metabolic Rate (BMR) using the Mifflin-St Jeor formula. A conservative Physical Activity Level (PAL) estimate of 1.4 was used to estimate actual TDEE. Then, the hypothetical PAL required in order for IBW TDEE to match actual TDEE was derived – the “physical activity level equivalent” (PALE). Of 1,102 patients recruited, 67% were female, with a mean age of 46.8±11.9 years, total weight 130.6±25.6 kg, excess body weight was 60.7±22.6 kg, IBW was 69.9±7.7 kg and BMI was 46.7±7.8 kg/m². The average theoretical PAL required for patients to achieve their current TDEE if they were at their IBW was 2.03±0.25 units. Estimates of current TDEE in patients with severe obesity, even when conservative estimates of actual physical activity are assumed, suggest that if they were to try to match that TDEE at their IBW, they would need to have long periods of sustained and vigorous physical activity. Whether discussing the “PALE” with patients is helpful or effective in motivational interviewing remains to be determined.