Physical activity and obesity prevention: a review of the current evidence

Abstract

Ecological data on temporal trends suggest that the rising prevalence of obesity is, at least in part, attributable to declining population energy expenditure. However, population-level data on trends in physical activity are scarce. In longitudinal cohort studies individuals who report higher levels of leisure-time physical activity tend to be less likely to gain weight, but studies vary in their conclusions because of issues of confounding, reverse causality and measurement error. The majority of studies suggest that low levels of activity are only weakly associated with future weight gain. Questions about dose–response can only be properly addressed by studies including objective measures of activity with known measurement error. The observational studies leave uncertainties about the direction of causality, as individuals who are overweight are less likely to stay active. Adjustment for confounding can diminish the impact of known confounders, but only randomisation can deal with issues of unmeasured confounding. Although there are a large number of clinical trials on the treatment of individuals with obesity or the prevention of weight regain among weight losers, the updated review of trials to prevent weight gain de novo only reveals six trials published since 2000 in adults and eleven in children. Not only are these trials relatively few in number but, for various methodological reasons, they are uncertain in their conclusions about whether increasing activity will be effective in preventing obesity. Whilst efforts should continue to enhance the evidence base it is wise, in the meantime, to stick to the consensus public health advice of advocating 45–60 min moderate intensity activity daily to prevent obesity.

Energy balance and obesity: a UK perspective on the gluttonyv.sloth debate

“…Within the Foresight programme, Wareham (45) summarised his previous review of the evidence base relating physical activity and obesity prevention (86) which had concluded that the ecological evidence for the increasing obesity prevalence to have occurred simultaneously with reductions in physical activity was rather limited. This reflected the limited validity of measures of total energy expenditure calculated from self-report data as used by the main source of information for the UK, The Health Survey for England (HSE) (2) .…”

Weight Change Over Eight Years in Relation to Alcohol Consumption in a Cohort of Continuing Smokers and Quitters

“…We explored this in an exsmoking population using data from the Health Survey for England. We found a small positive association between alcohol intake and physical activity, but this was far less than the additional daily 45-60 min of moderate activity required to prevent weight gain (Saris et al, 2003;Wareham, van Sluijs, & Ekelund, 2005). We found inconsistent associations of nine indicators of a healthy diet with alcohol consumption.…”

The interaction of diet and physical activity in managing obesity

“…The above reviews also concluded that the asso ci ations between higher phys ical activ ity and less weight gain are stronger if phys ical activ ity is meas ured at the end of the follow-up, or if the change in phys ical activ ity from baseline is used as the expos ure vari able Summerbell et al , 2009;Wareham et al , 2005). However, these analyt ical designs are in fact crosssectional (retro spect ive) in their design, not prospect ive.…”

“…The term 'weight gain' in this chapter includes also waist circum fer ence and body fat, if not indic ated other wise. Cohort studies on the asso ci ation between phys ical activ ity and weight gain have been system at ic ally reviewed by several authors during the last ten years Summerbell et al , 2009;Wareham et al , 2005). All of there three system atic reviews came to a similar conclu sion: there is suggest ive evidence that low levels of phys ical activ ity at baseline predict future weight gain, but the magnitude of effect is modest.…”

“…Daily phys ical activ ity is a sum of several kinds of activ it ies which take place in differ ent settings (work, home, commut ing) and have varying intens it ies and energy expendit ures. Moreover, part of the time spent in low phys ical activ ity can be clas si fied as totally sedent ary (sitting or lying) and this compon ent has also recently been asso ci ated with, e.g., obesity (Summerbell et al , 2009;Wareham et al , 2005) and mortal ity (Petersen et al , 2014).…”