For the majority of adults, weight gain throughout life is an unwanted consequence of the lifestyles they have chosen to live. A few extra snacks here, a second helping of food there, and the lure of the couch instead of the park adds up to mid-life mid-riff spread.
I’ve heard plenty of anecdotes about people who have gained several kilograms from a single weekend of over-indulgence. It is almost impossible though to gain several kilograms of body fat in two days. Short-term fluctuations in body weight is explained by fluid balance and changes in glycogen stores (the body’s main reserve of carbohydrate).
Real changes in body fat take much longer periods of time to show up. Over a year, an extra kilogram of body fat may not seem like much, but it adds up to a supersized problem when it happens year after year.
Discussion on diets and exercise have really been done to death and there are no real shortcuts here. Populist messages from vocal zealots pushing whatever is the evil food or nutrient du jour may appear to explain why we gain weight, but the truth comes down to plain old overeating.
Giving the cold shoulder to the diet and exercise debate, a really novel research study  has just been published answering the question of if there are ‘danger’ periods when someone is more likely to gain weight. The obvious time period to look at was the main holiday period of the year. Because it was an American study, the researchers looked at how body weight and health markers changed from Thanksgiving (occurring in late November) to New Year’s Day.
Putting some hard numbers to the tighter belts felt by many as a consequence of holiday over-indulgence efforts, the 148 people in the study gained an average of 0.78 kilograms each. With the rise in weight, so too did blood pressure. Systolic blood pressure (the higher of the two readings) was up 2.3 mmHg and diastolic (the lower number) shot up 1.8 mmHg.
It was bad news for people who were already carrying far too much weight going into the holiday season. People who were already obese saw their body fat percentage head north by 1.6 percentage points. Having a high body weight to start with also meant you were more likely to gain weight.
Surprisingly, exercise did little to blunt weight gain with both exercisers and non-exercisers gaining a similar amount of weight. Exercise does make a small, but important inroad into body weight. Faced with the abundance of food to eat over the holiday period though, only the truly dedicated activity buffs would likely see a benefit on their weight.
Research done before this latest study validates the finding that weight gain over the holiday period is a real waistline hazard. Well-meaning New Year’s resolutions though do little to shift the accumulated weight; once the weight is on, it is normally there to stay.
What it all means
Holiday times are loved by all. Unfortunately, our love for feasting at this time is not as good for our health. A single day of over-eating makes little difference on someone’s weight, but a sustained eating celebration does. Holiday times are a danger zone for weight gain, and contribute to the majority of weight gained over the course of the year. Next holiday period, be forewarned and prepared. Making eating healthy the goal for almost all of your meals, and enjoy the feeling of being fed, but not stuffed.
Confused about the mixed soup of nutrition messages being stirred through the media? Tim maintains an active nutrition blog at www.thinkingnutrition.com.au  where you'll find the latest nutrition research and controversies discussed in straight forward language, distilling out what you need to know for your better health.