Does physical activity equally predict gain in fat mass among obese and nonobese young adults?

Abstract

Background: Differences in energy metabolism and physical activity (PA) may contribute to the long-term regulation of body weight (BW). Objective: To examine the associations between metabolic determinants, energy expenditure and objectively measured components of PA with change in BW and fat mass (FM). Design: Prospective (4 years.), case-control study in obese (n ¼ 13) and normal weight (n ¼ 15) young adults. Measurements: At baseline, we measured resting metabolic rate, substrate oxidation, movement economy (ml O 2 kg À1 min À1 ), aerobic fitness (VO 2max ), total and PA energy expenditure by doubly labelled water, and PA by accelerometry. Fat mass was measured by DXA. At follow-up we repeated our measurements of PA and FM. Results: Fat mass increased significantly (Po0.001) in both groups. Physical activity did not change between baseline and 'follow up'. Change in overall PA (counts per minute) was inversely associated with change in BW and (b ¼ À0.0124, P ¼ 0.054) and FM (b ¼ À0.008, P ¼ 0.04). Post hoc analyses suggested that this association was explained by changes in the normal weight group only (b ¼ À0.01; P ¼ 0.008; and b ¼ À0.0097; P ¼ 0.009, for BW and FM, respectively). Metabolic determinants, energy expenditure estimates and subcomponents of PA (i.e. time spent at different intensity levels) were not significantly associated with change in BW or FM. Conclusion: Our results suggest an independent association between PA and FM. However, this association may differ depending on obesity status. The gain in FM, without any change in PA, may suggest that dietary intake is the major contributor to the positive energy balance.

Relative contribution of energy intake and energy expenditure to childhood obesity: a review of the literature and directions for future research

“…Ekelund et al 63 examined the relationship between changes in weight, fat mass and physical activity among obese and normal weight adolescents in Sweden. They found that both the normal weight and obese groups gained weight and fat mass over the 4-year follow-up period.…”

Ingesta y metabolismo energético en una muestra de adolescentes chilenos con sobrepeso y obesidad

“…asimismo, en un estudio transversal en preadolescentes, los índices de adiposidad estuvieron inversamente relacionados con las horas de actividad física moderada y vigorosa 13 . Sin embargo, en un estudio de seguimiento en adultos jóvenes, se observó que a pesar que la intensidad de la actividad física no varió en el tiempo (4 años), sí lo hizo la grasa corporal, sugiriendo que esta ganancia se debería a un aumento de la ingesta, la que no fue cuantificada 12 . Nuestro estudio coincide con un reporte previo en el que se señala que los niños y adolescentes que consultan por obesidad tienen una ingesta adecuada, pero una actividad física muy deficiente 15 .…”

“…Hay controversias en relación a cual sería el factor predominante en la génesis del sobrepeso en la población pediátrica, probablemente por la diversidad de diseños utilizados y por las diferencias socioculturales entre las muestras [12][13][14] . a nivel nacional, en escolares de centros educacionales de la Región Metropolitana, una evaluación cualitativa reveló que la calidad de los hábitos de ingesta era mejor que los de actividad física 11 .…”

The Utility of Shorter Epochs in Direct Motion Monitoring

“…NIH-PA Author Manuscript NIH-PA Author Manuscript moderate and vigorous physical activity (MPA and VPA) children routinely perform and how these levels relate to obesity (Ekelund et al, 2007;Pate et al, 2002).…”