We only measured up to four hours after the meal to get a snapshot of how the participants were coping with overeating. If we measured a longer period – six or eight hours, for example – we may have seen some more differences, especially because blood fat concentrations remain elevated for longer. However, our results tell us that one meal of overeating doesn’t cause much harm for your health – although 24 hours of overeating does seem to have an effect. So the focus of further research may be to understand how our bodies cope with the next meal after a binge.
Understanding how the body copes so easily with occasions of extreme calorie intake helps us understand what goes wrong in the long-term. Healthy humans rely on the body’s ability to work harder in times of need (by increasing insulin, gut hormones and heart rate) to maintain metabolic control. When we repeatedly eat too many calories at each meal, metabolic syndrome (a combination of high blood pressure, diabetes and obesity) will ensue and the body becomes unable to react to these situations.
Before starting the study, we were expecting the body to struggle with the huge calorie surplus of overeating. Our results show the body’s remarkable capacity to cope with the stress of eating too much food, by tightly regulating blood sugar concentrations and blood pressure. Throughout history, the human body has had to cope with periods of famine and abundance – this study is another demonstration of that evolutionary adaptation.
Though we focused on young, healthy participants, it will be important to now look at how the body copes with overeating in people who are overweight or at risk of disease, such as type 2 diabetes. But while overeating sometimes may be normal – and doesn’t pose too much of a risk to our health – it’s important to stress that eating more than we need on a regular basis isn’t healthy. This is partly because eating more calories than are required over a long period of time will lead to weight gain, and could lead to metabolic disease.
Aaron Hengist, PhD Candidate, Department for Health, University of Bath; James Betts, Senior Lecturer in Nutrition, Metabolism and Statistics, University of Bath, and Rob Edinburgh, PhD Candidate, Health, University of Bath