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We ask the experts to settle common questions we've all wondered about.

QUESTION: I've heard people claim they've gained five pounds after eating a large Christmas or Thanksgiving dinner. Is there really such thing as "holiday meal syndrome" and how much can your weight normally fluctuate in one day?

ANSWER: For those who overindulge during a holiday meal and then starve the next day in hopes of bringing the scale back to neutral, save yourself the insanity and understand that daily fluctuations in body weight are normal. Even if you've conquered a heaping plate of turkey, mashed potatoes and gravy, keep in mind that in order to gain one pound of body fat, you need to eat 3,600 more calories than what you regularly burn in a day. It's not a wise idea to gorge on a holiday meal in excess of 3,500 calories, but it may not be the only cause of your weight fluctuation the next day.

Although the short-term effects of a large meal can last several days, dietitians are more concerned about an additive effect. If an individual consumes several large consecutive meals, the body has difficulty regulating weight, which can lead to an increase in body fat over time.

The best way to obtain a true measure of body weight is to step on the same scale, at the same time, once a week; morning is best. After four weeks, take an average of these weights to ensure a more accurate depiction of your body weight. Conversely, daily weigh-ins can be misleading due to artificial weight fluctuations caused by varying factors. They're also irrelevant to long-term weight-loss goals.

Fluctuations in body weight can be caused by an interaction of four key variables, including: fluid retention, excess sodium intake, hormonal changes, and the actual weight of food consumed.

A high-salt diet can increase fluid retention. This artificial "weight gain" can cause daily weight fluctuations and skew body-weight measurements.

Unfortunately, the average Canadian eats double the recommended amount of salt every day, processed food being the primary culprit. More bad news, most of our Canadian foods, such as bread, cereals, packaged snacks and frozen meals, have 30 per cent more salt than similar products from any other country in the world. So Canadians must be even more conscientious at choosing lower sodium options and watching salt intake to minimize weight fluctuation and risk of developing high blood pressure.

Hormonal changes, especially in women, can also encourage natural water retention, resulting in weight fluctuation.

Furthermore, the body can retain fluid in ways that are not related to salt or hormones; drinking water and being well-hydrated can actually reduce bloating.

Finally, the actual weight of the food affects body weight, underscoring the importance of moderate portions. A solid bowel movement can relieve up to five pounds.

While these four factors can result in daily weight fluctuations of between two and seven pounds in a healthy person, changes of 10 pounds or more, coupled with other symptoms (such as shortness of breath, extreme fatigue or pain) may require medical attention. Rapid declines or increases in weight might be signs of thyroid deregulation, heart problems, or undiagnosed diabetes. Medications can also impact fluid balance and therefore body weight so consult the pharmacist when taking new medications and always take medication as prescribed.

Eating a variety of healthy foods is important to keep the body nourished, but it's also vital to eat at regular times and maintain consistent meal sizes to lose weight. A regular routine is shown to positively affect physiological processes in the body and lower the risk of weight gain and disease. Consequently, yo-yo dieting is a risky strategy because varying body weights - high and low - are imprinted in the body's physiological system. The more weight fluctuations one has, the harder it is for the body to return to a set point.

It is important to remember there is not one "ideal weight" for everyone. Maintaining a consistent body weight over time is protective against chronic diseases including cancer, fatty liver disease and heart disease.

While overindulging may seem unavoidable this holiday season, it's not. Try to keep your eating patterns in check because too much too often is harmful in the long run.



Nishta Saxena is a clinical dietitian for the Peter Munk Cardiac Centre at the University Health Network in Toronto.



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