Effects on eating behaviour and taste preferences
IS are often consumed as sugar substitutes, particularly
in beverages, in order to satisfy a desire for sweetness
while avoiding energy intake from sugars. The expert appraisal
assessed whether there were metabolic consequences
of this separation of sweetness and calorie
intake, particularly in terms of body’s ability to associate
a taste with an energy value and therefore regulate its
energy balance, and also in terms of consequences of IS
consumption on appetite for sweetness and the consumption
of sweet products.
Data in adults
A meta-analysis covering studies undertaken before
2006 along with around ten randomised experimental
studies were identified to address these points. The
meta-analysis of 15 randomised experimental studies [9]
assessed the effects of aspartame consumed alone or with
other (unspecified) IS on food and energy intake during
the course of a day in adults. These measurements
covered a limited number of subjects (less than 30) and
highly variable time periods of a few days to 16 weeks.
The main inclusion criterion for studies in this metaanalysis
was the measurement of food intakes for at least
24 hours, to assess the full extent of any compensatory
effects of the various meals consumed over the day. The
authors conclude that consuming aspartame as a sugar
substitute results in a decrease of daily energy intake by
220 Kcal on average. Moreover, the authors indicate that
this substitution may be more efficient in beverages than
in solid foods, since the energy supplied by liquids leads to
less satiety than that supplied by solid foods. In fact, the
estimated compensation rate is thought to be lower for
sugars consumed in liquid form than in solid form [10].
Therefore, according to these authors, the reduction in
energy intake due to the replacement of sugar with sweeteners
is greater with artificially sweetened beverages than
with artificially sweetened solid foods. However, the conclusions
of this meta-analysis should be treated with
caution, due to several methodological limitations, particularly
a lack of essential information on the study selection
process, the assessment of their quality and the
statistics applied to assess the heterogeneity of the data
taken into account. Other experimental studies (that were
not included in the meta-analysis since they covered periods
of less than 24 hours) analysed the effects of IS on
appetite and food intake. These studies used an IS preload
approximately one hour before a meal, generally in beverage
form (rarely in solid form, i.e. in a food), and measured
food intake and calorie intake during the next meal.
All of these studies showed that irrespective of the nature
of the tested IS, a preload reduced the sensation of hunger
and the desire to eat, with a maximum effect immediately
after its consumption. However, this effect tended
to disappear before the start of the meal, which explains
why most studies did not observe reduced food intake
during the meal after the preload. Regarding food preferences,
several studies assessed the effect of IS on the
perception of sweetness (gustatory stimuli) and/or taste
preferences for foods. Several studies showed that preference
for a sweet food was independent of the sweetening
agent (i.e. no difference between an IS and
sucrose), but their results differed as to the repercussions
of this preference on consumption of this food.
However, these studies had extremely variable protocols
and objectives, to the extent that it is difficult to compare
their results and draw an overall conclusion on
the effect of IS on food preferences.
Overall, based on studies dealing with occasional exposure
to an IS before a meal, it is not possible to infer
the effect of regular IS consumption on sweetness habituation
or increased cravings for sweetened products.
Most experimental studies show that the occasional consumption
of IS before or during a meal has no effect on
food intake or energy intake during the next meal. Occasional
IS consumption before a meal reduces the sensation
of hunger and the desire to eat, just like caloric
sweeteners, but this effect is temporary and disappears
before the start of the meal. In most cases, the use of IS
as sugar substitutes results in a decrease in short-term
energy intake due to their low calorie content and the
lack of compensation. However, the available data cover
insufficient time periods to guarantee the maintenance
of this effect over the medium or long term.
Data in children
Preference for sweetness is innate. It is strong at birth and
then tends to decrease. However, it seems to be maintained
by the repeated consumption of sweetened foods
or beverages during early childhood [11]. A study [12]
showed that adding aspartame or sucrose to milk favoured
its consumption. Moreover, the work of Birch and their
collaborators revealed that children preferred flavours associated
with calorie intake, suggesting that sweetness itself
is not sufficient to generate food preferences, and that
energy density, just as much as (or even more than) sweetness,
can determine food preferences [13, 14]. However,
there are no data showing whether IS have a specific effect,
in relation to caloric sweeteners, on the development
of taste and food preferences. A study compared the effects
of consuming 250 mL daily of artificially sweetened
beverages vs sugar-sweetened beverages on the satiety
and desire to eat of children aged seven to 11 years
for 18 months [15]. The level of satiety was the same,
irrespective of the beverage consumed.
In conclusion, based on the available studies, it is not
possible to determine whether IS consumed during early child hood have a specific effect on the development
of taste and food preferences or on the shortand
medium-term regulation of food intake.