A Guilt Free Holiday Period! – Kirby Harley AEP

A Guilt Free Holiday Period!


Quite often you hear people worried about the overconsumption of food during the Christmas and New Year period, to then go on and make unrealistic and unattainable weight loss goals because they feel guilty about enjoying their food during this time.


In order to gain weight, your energy intake must exceed your energy expenditure for an extended period of time (overconsumption of calories for a week or two will not result in you gaining excessive amounts of weight). Joosen and Westerterp (2006) indicate that weight gain develops when energy intake (EI) exceeds energy expenditure (EE) for longer periods of time. However, overfeeding experiments show that weight gain is often less than expected from the energy excess. Now, I’m not sure about you, but during this holiday period I’m not exactly sitting still all day. We are rushing from here, there and everywhere, running after kids, swimming, cooking and cleaning and again being anything but sedentary. This is what we like to call NEAT or non-exercise activity thermogenesis. This is the energy we expend for all activities except for eating, sleep and exercise. Did you know, that by performing these activities we are also increasing our energy expenditure, and subsequently balancing the scales between what we eat and what we expend?!!


This is where I also want to introduce you to adaptive thermogenesis. Adaptive thermogenesis is defined as the regulated production of heat in response to environmental changes in temperature and diet (Dulloo et al. 2012). Essentially, humans adapt to changes in food intake through adaptive thermogenesis, by turning down the rate of heat production during energy deficit (so as to conserve energy) or turning it up during overnutrition (so as to dissipate excess calories). So, the coming two weeks will not provide enough of an energy intake stimulus to make a massive difference on the scales, because as well as our accumulative NEAT, our body also increases the rate of heat production to utilise excess energy intake. In fact, due to our body’s great ability to adapt to multiple stimuli, it would require weeks of overeating in order to have a significant impact on the scales.


In short, don’t feel guilty for eating that extra slice of pav, or having a few extra bevvies. You don’t need to make unrealistic goals, because you feel bad about your exercise and diet routine during the holiday, because it’s just that – holidays. Enjoy this time with your family and friends, be realistic, enjoy that honey glazed ham, the jelly slice and the beer. It won’t be detrimental, as your body is well equipped to adapt for that short period of time.






Dulloo, A., Jacquet, J., Montani, J., & Schutz, Y. (2012). Adaptive thermogenesis in human body weight regulation:more of a concept than a measurable entity?. Obesity Reviews13, 105-121. doi: 10.1111/j.1467-789x.2012.01041.

Joosen, A., & Westerterp, K. (2006). Energy expenditure during overfeeding. Nutrition & Metabolism3(1). doi: 10.1186/1743-7075-3-25