It’s quite common for most people to eat late or indulge in snacks after dinner. Many a times it is stress that drives people to binge eat and indulge in snacks, chocolates, ice creams and anything that makes them feel satiated.
But little is known about how the time of day and stress interact to affect appetite and thus body weight.
To understand this researchers conducted experiments with 16 obese participants and 16 participants without Binge Eating Disorder (BED). Out of the 32 participants there were 19 men and 13 women between the ages of 18 and 50 years. 47 percent of the participants were African American. The body mass index of the participants ranged from 28 to 52 and they were otherwise healthy.
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Previous studies have shown that a hunger hormone called ghrelin can rise in response to stress during the daytime.
To understand how stress might affect hunger pangs especially in those with binge eating disorders as they tend to overeat later in the evening, the researchers measured the participants’ hunger and stress hormones levels at different times.
The participants fasted for eight hours and then received a liquid meal of 608 calories at either 9 am or 4 pm.
Each participant then underwent a standard stress experiment approximately 130 minutes after the meal where their non-dominant hand was submerged in a bucket of cold water for two minutes while a digital camera recorded their facial expressions.
The researchers took blood samples to measure stress and hunger hormones and participants were also asked to rate their subjective levels of hunger and fullness on a numeric scale.
After 30 minutes from the start of the stress test, the participants were offered a range of attractive food options such as three medium pizzas, individual containers of snack chips, cookies and chocolate covered candies, and water.
The researchers found that the time of the day had a significant impact on hunger levels with the baseline hunger levels being greater as self-reported than the levels in the morning.
There was also a decreased level of peptide YY – a hormone linked to reduced appetite, insulin and glucose levels – in relation to the liquid meal.
Those with binge eating disorder also showed more hunger levels or lower levels of fullness in the evening and they also had higher initial ghrelin levels in the evening and lower ghrelin levels in the morning compared to those who didn’t have the disorder.
After the stress test, the study also found slowly increasing stress levels and hunger levels in all participants However, the ghrelin levels were higher in the evening suggesting that stress influences this hormone and particularly in the evening.
Evenings seem to be a high-risk time for overeating and especially when one is stressed as this can lead to many problems particularly in people who are already overweight, obese or have binge eating disorders. But by understanding how stress can affect hunger levels at particular times of the day, people can be prepared for it and find alternative times to eat (earlier) in the day or find methods of reducing their stress levels.
Source: International Journal of Obesity
