Why is it that even when we have the best of intentions, dieting is so difficult?
THE UK’s diet industry is thriving to say the least.
More
than half of British adults try to lose weight by controlling their
calorie intake each year. Unfortunately, losing weight is not as easy as
turning down a biscuit, or opting for salad. And even those who have
been successful in their dieting endeavours find it difficult to do.
So why is it that even when we have the best of intentions, dieting is so difficult? Why can’t we control those cravings?
1. Food cues
We’ve
all done it: walked past a tasty-looking supermarket stand, or smelled
something delicious and immediately started drooling over whatever treat
is on display, regardless of calorie content or nutrition.
Sensory
food cues like these can be difficult to ignore and aren’t just
triggered by taste or smell — advertising or brand logos can tempt us in
too.
When we are hungry, the hormone gherlin stimulates the brain, which means that we notice food cues more.
Source:istock
Researchers
have also found that our brains pay more attention to cues for
unhealthy foods — those which are high in sugar and fat — than healthy
foods, when we are hungry. In studies where pictures of high-calorie
foods were shown to participants, it was found that the cues elicited
anticipatory appetite responses, such as salivation, cravings and a
reported desire to eat.
All of this together means that the
attention-grabbing properties of high-calorie foods are likely to
present a significant challenge for individuals who are attempting to
lose weight — particularly if their diet makes them feel hungry.
On a positive note, it may be possible to train ourselves to ignore
tempting cues. One study has shown that participants who were taught to
ignore high calorie food cues on a computer-based task consumed less
snack foods than those who were trained to pay attention to them
2. Forbidden foods are more tempting
In
another study, frequent consumers of chocolate were asked not to eat
any for a week. In this case the participants found images of chocolate
and other high-calorie food items more salient — the deprivation had
made them want the high calorie foods more — than the chocolate eaters
who had not been deprived.
In addition, when asked to taste a
forbidden food, it has been found that research participants who have
been deprived of it will typically consume more calories.
All of
this means that even when dieters attempt to avoid foods that are
pleasurable, the behavioural and cognitive response to deprivation may
inadvertently be creating more temptation.
3. The “what-the-hell” effect
When
trying to lose weight, choices about what to eat and when it should be
eaten are usually constrained by the rules of a chosen diet plan. But
rigid dieting rules are problematic, as any eating behaviour that does
not rely on the physiological signals of hunger increases the risk of
overeating.
Another problem with dieting rules is that only a
small violation — a sneaky slice of cake, for example — is enough to
derail the whole diet.
Researchers call this the “what-the-hell
effect” — and it has been demonstrated in a number of laboratory
experiments. Studies consistently show that dieters who believe they
have consumed a high-calorie snack — and so have broken the rules of
their diet — will consume more calories during a later meal than those
who do not think they have violated the rules.
Although
in real terms eating a few extra calories is unlikely to have a major
impact on a diet, such lapses can have a bigger psychological impact.
Dieting “failure” is likely to trigger negative emotions such as guilt
or stress, both of which are known to cause overeating.
So what
can be learned from all of this? Diets which require the dieter to
follow rigid rules or forbid them from consuming foods they enjoy appear
to be problematic, as they paradoxically increase the risk of
overeating. Instead, it may be useful for dieters to acknowledge that
humans are inherently drawn to high-calorie foods and that these cues
present the most temptation if we are hungry.
Rising rates of
obesity mean that many more of us are turning to diets to lose weight.
However, while there is no perfect diet to help us achieve our health
goals, understanding how the brain works, and recognising the
psychological effects of dieting may help us regain control in the face
of temptation.
No comments:
Post a Comment