Stability of Metabolic Factor Before and After Bariatric Surgery.

BACKGROUND: A new metric called metabolic factor (resting metabolic rate/weight) has previously been established that can differentiate between people who are obese, overweight, and of normal weight. Previous studies were re-analyzed and found that people who lost weight did not experience a change in their metabolic factor.

MATERIALS AND METHODS: The current study measured the metabolic factor of 18 individuals before and after bariatric surgery.

RESULTS: As expected, individuals lost nearly 100 lb and therefore lowered their resting metabolic rate from 2614.3 to 1954.4 kcal (p < 0.05). However, the pre-operative metabolic factor of 8.1 (1.1) cal/lb did not change significantly as it slightly increased to 8.6 (0.88) after surgery (p = 0.19). Weight loss was not statistically significantly correlated with change in metabolic factor (r = 0.22). The follow-up metabolic factor negatively correlated with post-operative BMI, r = -0.48 (p < 0.05), indicating the higher the metabolic factor, the lower the post-operative BMI.

CONCLUSIONS: This study seems to establish the possibility that metabolic factor is not simply a function of one's current weight, but instead might be a stable characteristic unique to each individual.