It's well accepted that reduced physical activity and fast food are linked to obesity. But the evidence that these are the main causes of obesity is largely circumstantial. To stimulate debate, experts suggest 10 other possible causes of obesity, outlined in the International Journal of Obesity.

   1. Sleep debt. Getting too little sleep can increase body weight. Today, many get less shut-eye than ever.

   2. Pollution. Hormones control body weight. And many of today's pollutants affect our hormones.

   3. Air conditioning. You have to burn calories if your environment is too hot or too cold for comfort. But more people than ever live and work in temperature-controlled homes and offices.

   4. Decreased smoking. Smoking reduces weight. People smoke much less than they used to.

   5. Medicine. Many different drugs including contraceptives, steroid hormones, diabetes drugs, some antidepressants, and blood pressure drugs can cause weight gain. Use of these drugs is on the upswing.

   6. Population age, ethnicity. Middle-aged people and Hispanic-Americans tend to be more obese than young European-Americans. Americans are getting older and more Hispanic.

   7. Older moms. There's some evidence that the older a woman is when she gives birth, the higher her child's risk of obesity. Women are giving birth at older and older ages.

   8. Ancestors' environment. Some influences may go back two generations. Environmental changes that made a grandparent obese may "through a fetally driven positive feedback loop" visit obesity on the grandchildren.

   9. Obesity linked to fertility. There's some evidence obese people are more fertile than lean ones. If obesity has a genetic component, the percentage of obese people in the population should increase.

  10. Unions of obese spouses. Obese women tend to marry obese men, and if obesity has a genetic component, there will be still more obese people in the next generation.

These other contributing factors deserve more attention and study. Even more explanations include: a fat-inducing virus; increases in childhood depression; less consumption of dairy products; and hormones used in agriculture. What do you think can be attributed to the epidemic?

Daily Health Tips Blog

Many of us make health-related resolutions, such as to lose weight, stop smoking or join the neighborhood health club. While it is common to set high goals, experts say that setting smaller goals could do more for our health.

"Small steps are achievable and are easier to fit into your daily routine," says James O. Hill, Ph.D., Director of the Center for Human Nutrition at the University of Colorado Health Sciences Center. "They are less overwhelming than a big, sudden change."

Here are 10 to try:

1. Stop gaining weight. Even if you gain just a pound or two every year, the extra weight adds up quickly.

2. Take more small steps. Use a pedometer to count your daily steps; then add 2,000, the equivalent of one extra mile. Keep adding steps, 1,000 to 2,000 each month or so, until you take 10,000 steps on most days.

3. Eat breakfast. Breakfast eaters tend to weigh less and have better diets overall. For a filling and nutrition-packed breakfast, top Whole Grain Total® with fresh fruit slices and low-fat or fat-free milk.

4. Switch three grain servings each day to whole grain. If you're like the average American, you eat less than one whole grain serving a day.

5. Have at least one green salad every day. Eating a salad (with low-fat or fat-free dressing) is filling and may help you eat less during the meal. It also counts toward your five daily cups of vegetables and fruits.

6. Trim the fat. Fat has a lot of calories, and calories count. Purchase lean meats, eat poultry without the skin, switch to lower-fat cheeses, use a nonstick pan with only a dab of oil or butter.

7. Consider calcium by including two or three daily servings of low-fat or fat-free milk or yogurt. Dairy calcium is good for bones and may also help you lose weight.

8. Downsize. The smaller the bag, bottle or bowl, the less you will eat.

9. Lose just 5 to 10 percent of your current weight. The health benefits are huge-lower blood pressure, blood sugar, cholesterol and triglycerides.

10. Keep track of your eating. Write down what you eat over the next couple of days and look for problem spots. Often, just writing things down can help you eat less.

Daily Health Tips Blog