Lots of people claim that eating “comfort” foods such as chocolate when they feel depressed or a bit low helps to improve their mood. This is often dismissed as just another excuse to indulge in fatty and sugary foods and that eating a piece of fruit would work just as well. But according to some recently published research, eating fat seems to make us less vulnerable to sad emotions, even when we don’t know we are eating fat.
A team of scientists at the University of Leuven, in Belgium, used MRI brain scans to assess the emotional impact of fat when injected into the stomach. They recruited 12 healthy-weight volunteers and scanned their brainwaves as they were shown a series of sad and neutral images as well as exposing them to sad and neutral music. They then infused a solution of either fatty acids or saline directly into the stomachs of the volunteers, but without telling them which they were having. This meant they could bypass the effects of taste and smell on the volunteers’ reactions. The scientists found the music and images resulted in a lowering in the mood of all the subjects, but the levels of sadness in those given fats were only 50% of those who were given saline. So it seems that there really is an intimate “gut-brain conversation” and that certain types of foods rich in fat (including chocolate bars and ice-cream) may help raise our spirits when we feel sad. Comfort eating has a real basis in physiology.
Of course knowing this doesn’t really help much if you are trying to lose weight. And for some it will be a way to justify reaching for the chocolate biscuits (any excuse will do, but if there is a bit of science around to help all the better). Fortunately there is a potential solution to this dilemma; it’s called physical activity.
There is abundant scientific evidence to show that regular exercise improves mood, lifts depression and reduces stress and anxiety. In fact studies have shown that even a single session of brisk walking for 30 minutes improves mood and reduces depression scores. These effects are probably due to increased brain levels of special chemical transmitters such as serotonin and endorphins which are known to enhance mood, though there are probably other mechanisms at work.
The problem is that if you have the blues, going for a brisk 30-minute walk is far less attractive than grabbing a chocolate bar. But if you can do it once, you’ll find it much easier the next time. It’s also the case that although the chocolate will make you feel better for a short while, later on you’ll be feeling even more depressed because you gave in to your craving (evidence shows that cravings are actually quite short-lived anyway). On the other hand if you take the walking option you’ll have improved your mood, increased your fitness and enhanced your weight loss.
Many people focus on eating, drinking and what they are craving with almost no thought for physical activity. This is a shame, because whether we like it or not, being physically active is an essential part of weight loss and long-term weight maintenance. So the next time you feel a bit low do yourself a big favour; give the fridge a miss and get your coat on.
Dr David Ashton MD PhD
14th February 2012