In a Meta-analysis recently published in the British Journal of Medicine (January 2013), the authors reviewed over 30 published trials & 38 published cohort studies related to sugar intake. Their goal was to identify trends across these 68 publications related to sugar consumption and effect on body weight.
In their evaluation, they concluded there does appear to be a direct correlation between consumption of sugar and body weight. Additionally, they found the odds ratio (or probability) of being overweight or obese was highest among groups with the highest intake of sugar or sugar-sweetened beverages. The studies that were reviewed included both adult and child subjects. Some of the studies also evaluated the effects on cholesterol levels, changes in BMI, changes in blood glucose & insulin levels, mood, and inflammation.
The theory about the sugar-obesity connection stemmed from John Yudkin’s claim that sugar consumption was associated with heart disease in the 1970’s. His theory remains controversial, due to lack of strong data. However, a thorough meta-analysis such as this one lends credibility to his theory by identifying trends across many studies, over different time periods, and by various researchers.
The authors did not give a recommendation of the ideal consumption amount to prevent weight gain or obesity. However, based on these conclusions, further research studies can be designed to dive deeper and learn more about why and how this occurs.
(Te Morenga, et al. BMJ. 2012 Jan 15;346:e7492. doi: 10.1136/bmj.e7492.; Abstract available on pub med: http://www.ncbi.nlm.nih.gov/pubmed?term=23321486