the increasing prevalence of overweight and obesity
has called for actions already in place for years.
Unfortunately, the results so far have been mostly
disappointing. The role of science in combating obesity is
to provide evidence for decision-making at political
(national and local) level, in food industry, in health
care settings and in educational planning. Evidently,
more data are needed to understand the detailed aetiology
of obesity and how to combat obesity at population
and individual levels.
In addition to physical activity, diet is a major factor
affecting energy balance and subsequently weight change.
Most of the studies looking at the impact of diet on
weight change have concentrated on the proportions of
macronutrients (as percent in total energy intake, E%) or
on consumption of specific foods.
Recently, several systematic reviews and meta-analyses
have addressed the role of carbohydrates in obesity.
Cross-sectional studies tend to show an inverse relation
between the proportion of dietary carbohydrates (E%)
and obesity (1). In contrast, cohort studies and randomised
intervention trials do not provide strong evidence
that increasing or decreasing the proportion of dietary
carbohydrates has a significant independent effect on
body weight maintenance (1).
Sugar-rich foods are usually low in dietary fibre and at
least moderately high in energy density. In theory, both
properties could link high sugar intake with obesity. In an
extensive narrative review, van Baak and Astrup (2)
concluded that there is insufficient evidence that an
exchange of sugar to nonsugar (starch- and/or fibrerich)
carbohydrateswould assist in body weight reduction.
Very few population studies report on the association
between sugar-rich food intake and weight gain. In a study
using the EPIC cohort in Potsdam, Schulz et al. (3)
reported that intake of high sugar foods, i.e. sweets, was
significantly predictive of large weight gain. However,
there is stronger epidemiological (1, 2) and less consistent
evidence from randomised intervention trials (4) that
sugar-sweetened beverages may induce obesity.