Accelerometer-measured physical activity is not associated with two-year weight change in African-origin adults from five diverse populations

Abstract

BackgroundIncreasing population-levels of physical activity (PA) is a controversial strategy for managing the obesity epidemic, given the conflicting evidence for weight loss from PA alone per se. We measured PA and weight change in a three-year prospective cohort study in young adults from five countries (Ghana, South Africa, Jamaica, Seychelles and USA).MethodsA total of 1,944 men and women had baseline data, and at least 1 follow-up examination including measures of anthropometry (weight/BMI), and objective PA (accelerometer, 7-day) following the three-year study period. PA was explored as 1-minute bouts of moderate and vigorous PA (MVPA) as well as daily sedentary time.ResultsAt baseline; Ghanaian and South African men had the lowest body weights (63.4 ± 9.5, 64.9 ± 11.8 kg, respectively) and men and women from the USA the highest (93.6 ± 25.9, 91.7 ± 23.4 kg, respectively). Prevalence of normal weight ranged from 85% in Ghanaian men to 29% in USA men and 52% in Ghanaian women to 15% in USA women. Over the two-year follow-up period, USA men and Jamaican women experienced the smallest yearly weight change rate (0.1 ± 3.3 kg/yr; −0.03 ± 3.0 kg/yr, respectively), compared to South African men and Ghanaian women greatest yearly change (0.6.0 ± 3.0 kg/yr; 1.22 ± 2.6 kg/yr, respectively). Mean yearly weight gain tended to be larger among normal weight participants at baseline than overweight/obese at baseline. Neither baseline MVPA nor sedentary time were associated with weight gain. Using multiple linear regression, only baseline weight, age and gender were significantly associated with weight gain.DiscussionFrom our study it is not evident that higher volumes of PA alone are protective against future weight gain, and by deduction our data suggest that other environmental factors such as the food environment may have a more critical role.

The cross‐sectional associations between objectively measured sedentary time and cardiometabolic health markers in adults – a systematic review with meta‐analysis component

“…Most studies that examined body mass reported no association , except for the work by Dugas et al . , who found baseline sedentary time to be associated with body mass of Ghanaian male and female participants, positively and negatively, respectively. The same authors reported no associations for participants from South Africa, Jamaica, Seychelles and the USA.…”

“…Of the prospective studies identified, two used heart rate FLEX to measure sedentary time , with the remaining studies employing accelerometry . Follow‐up periods ranged from 2 to 5.8 years, with sample sizes ranging from 376 to 2,027 participants.…”

“…Of the prospective studies identified, two used heart rate FLEX to measure sedentary time , with the remaining studies employing accelerometry . Follow‐up periods ranged from 2 to 5.8 years, with sample sizes ranging from 376 to 2,027 participants. Sedentary time at baseline was not significantly associated with BMI , fat mass , waist circumference , SBP and DBP , lipid profile markers (total cholesterol, HDL‐C, LDL‐C and triglycerides) , glucose measures (fasting glucose, 2‐h glucose and HbA1C) , development of the metabolic syndrome and the majority of insulin measures (2‐h insulin, insulin sensitivity and insulin resistance) .…”

“…Prospective studies are the most methodologically rigorous observational studies in the absence of randomized controlled trials. To the authors' knowledge, <10 prospective studies using any objective measurement of sedentary time that also examined markers of CMH have been conducted among healthy adults (46,(76)(77)(78)(79)(80)(81). To supplement the indepth cross-sectional findings reported herein, the subsequent section briefly summarizes the prospective findings to date.…”

The ineluctable constraints of thermodynamics in the aetiology of obesity

“…Offering indirect support for the preceding contention are the results of a 3‐year prospective study of the correlation between physical activity (quantified by accelerometry) and weight change, in nearly 2000 men and women of African origin, aged 24‐45 years, resident in different locales in five different countries: rural Ghana, urban Jamaica, urban South Africa, the Seychelles and metropolitan USA . Multiple regression techniques failed to reveal correlations between level of activity and weight change by participants in any country.…”