When the holidays come around, sugar consumption skyrockets. Just think of all the Christmas cookies, candy canes, pies, and other specialty treats that you only see during that special season of the year.

It’s no wonder that the average weight gain for Americans from Thanksgiving to New Year’s is eight pounds. And if you don’t do anything to prevent it, that excess weight is likely to stay on throughout the next year.

To my chagrin, I found this out just last year. Though I tried to watch what I was eating, the steady stream of gift baskets of chocolates and candied cashews and walnuts delivered to my office showed me how easy it was to pack on a few pounds without even noticing it happening.

In some cases, the sugar in what we eat is obvious. Foods that taste sweet contain sugar. In fact, they probably contain more sugar than you think.

For instance, a 12-ounce can of soda contains the equivalent of nine cubes of sugar; a half-cup of gelatin, six cubes; and one-and-a-half cups of sweetened cereal contains 11 cubes of sugar.

But it’s not just the sugar bowl or the sweet foods that are causing problems. Because sugar, like salt, is a hidden ingredient in many foods, prized not only for the sweetness it adds, but for other reasons as well.

Sugar is used as a fermenting agent to help bread rise, it preserves jams and jellies, serves to bulk up ice cream, and even balances acidity in foods containing vinegar.

In fact, it’s estimated that 50 percent of the sugar consumed by Americans is hidden in foods such as:

• Ketchup

• Bread

• Crackers

• Salad dressing

• Cereals and oatmeal

Believe it or not, even foods that taste salty are likely to contain sugar.

It’s a well-known fact that sugar is fueling the obesity crisis, and that people who are 40 percent overweight are twice as likely to die prematurely as a person at a normal weight.

Less well-known is the fact that obesity is also creating an epidemic of Type 2 diabetes, the most common form of this metabolic disorder.

Both obesity and diabetes are major contributors to heart disease. Excess abdominal fat fuels inflammation, a key culprit in causing heart attacks. Diabetes doubles the risk of heart disease in men and triples it in women.

In addition, sugar is a direct cause of high triglycerides, the so-called “remnant” cholesterol that researchers are learning could be even more dangerous than LDL cholesterol, the “bad” cholesterol that has been blamed for heart attacks and strokes for decades.

But did you know that excess sugar could be a killer in itself ?

A recent study by University of Utah scientists found that when mice eat a diet of 25 percent sugar (the mouse equivalent of a healthy human diet plus three cans of soda), females died at twice the normal rate and males were less likely to compete for territory or reproduce.

This was the case even though the mice didn’t become obese or show other obvious signs of metabolic problems.