Research Updates | Obesity / Overweight
Pereria MA explored the methodological nuances across studies on SSB and weight gain/obesity risk in order to bring more clarity to the area. A secondary aim was to critically review the literature on the possible association between ASB and obesity risk.
The review was conducted via a Medline search of English papers published from 1946-2012. It included prospective cohort studies >6months in duration and RCTs with body weight or body fat as the outcome. Quantitative estimates of the association were also explored.
The totality of the evidence shows a pattern of increased risk of weight gain/obesity with high intakes of SSB. It is however difficult to establish the strength of the association and independence from other potentially confounding factors. There is somewhat consistent evidence that ASBs may be protective in preventing obesity vs SSBs.
The question still remains: Do ingested calories in liquid form have a greater impact on weight gain than calories in solid form?
This field needs high-quality experimental studies in humans, exploring the direct comparisons between SSB and their sweetened solid-food alternatives.
Future RCTs should address mechanisms of action, assess behaviours on both side of the energy balance equation, and ensure good measurement of background habitual diet, physical activity and other potential modifying factors.
Limitations: The paper is limited by the fact it is not a systematic review: only one database was searched and only English language papers included. It was concluded that science in this area is unlikely to progress without better quality studies.