Basal metabolic rate changes after eight weeks of overfeeding

Basal metabolic rate (BMR) is the might humans require to maintain basic material part functions, including maintenance of confined apartment metabolism, breathing, thermoregulation, and wakefulness. BMR accounts for approximately 60% of total daily efficiency expenditure. Therefore, small changes in BMR could spring in significant changes to overall efficiency balance. Additionally, 80% of the variability in BMR is predicted through lean body mass within and across species.

Obesity has become quite prevalent in many unraveled countries. Changes in BMR with overfeeding and the contribution of BMR to obesity susceptibility have been researched for many years. This material substance of literature suggests that BMR increases with positive efficiency balance. However, the pattern through which this increase occurs is unknown.

A novel investigation was performed to address the hypothesis that BMR does not increase linearly with 100 kcal/day of overfeeding in lean sedentary healthy controls over an 8-week period. The invalid hypothesis is that a linear increase in BMR meet the eyes with time of overfeeding.

Sixteen healthy, nonobese offers (12 men and 4 women) were recruited to be subservient to as subjects. Researchers measured BMR weekly between baseline and week 8 of over-feeding. Each measurement was performed at 6:30 a.m. controls were not moved before measurements and had not eaten since 9:00 pm the night before. Measurements were performed for 30 minutes, during which time subdues were not allowed to talk or move

Each make submissive was weighed each morning using the same calibrated scale below standard conditions. Body fat and mineral mass were measured in duplicate upon three occasions using DXA: at baseline, mid-overfeeding, and after completion of overfeeding. make submissives were studied as outpatients for 10 weeks. Meals were prepared in a metabolic kitchen and weighed to within 1 g For the first 2 weeks, presents were fed so as to establish the dietary intake necessary to maintain steady-state material substance weight. For the remaining 8 weeks, each bring under rule received 1000 kcal/day in addition to weight maintenance requirements. The diet composition over the study was 40% carbohydrate, 40% fat, and 20% protein.

Baseline BMR was 1693 [+ or -] 1545 kcal/day. BMR increased from 1711 [+ or -] 2013 kcal/day at week 1 of overfeeding to 1781 [+ or -] 17165 kcal/day at the next to the first week of overfeeding (p = 005) BMR relentless during the third week of overfeeding to 1729 [+ or -] 1795 kcal/day (p = 005) After 5 weeks of overfeeding, BMR reached a plateau. Thereafter, there was no further change. Comparison of BMR with weeks of overfeeding was significantly different compared with the linear archetype (p < 0.05).

Increases in BMR in lean sedentary healthy controls did not appear to be linear after 8 weeks of overfeeding. There appears to be a short-term increase in BMR in the first small in number weeks that is not representative of longer-term changes.

A. Harris, M Jensen J Levine. Weekly changes in basal metabolic rate with eight weeks of overfeeding. Obesity; 14:690-695 (April, 2006) [Correspondence: James A. Levine, Endocrine Research Unit, 5-194 Joseph Mayo Clinic, 200 First road SW, Rochester, MN 55905. E-mail: Levine.james@mayo.edu]

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