Editor's note: Dr. Melina Jampolis, CNN's diet and fitness expert, is a physician, nutrition specialist and the author of "The Calendar Diet: A Month by Month Guide to Losing Weight While Living Your Life."
(CNN) -- Q: Why do we crave comfort foods when the weather turns cold? And are there healthy substitutes?
This is an interesting question and one to which there is no simple answer.
There is considerable research showing seasonal affective disorder (SAD) -- which affects 1% to 3% of the population -- is linked to increased appetite and carbohydrate cravings, which are probably consumed in the form of "comfort foods." This is likely due to changes in brain chemistry brought about by the change in seasons and alterations in circadian rhythm, the body's biological clock.
Those who may not be clinically diagnosed with SAD may experience mild depression or worsening mood during colder, less sun-filled days due to more moderate changes in brain chemistry. Some studies suggest an association between vitamin D deficiency (common in winter months when sun exposure is limited in most of the country) and mood, so this may play a role.
People may also be less active and less social in the winter, which could increase anxiety and depression and lead to stress eating and overconsumption.
Comfort foods are generally sweet, fatty and calorie-dense, which may help temporarily improve mood and alleviate anxiety or stress. In other words, many people may be self-medicating with these dishes.
There are several other likely behavioral and biological components. Lighter, cooler foods like fresh fruits and vegetables were historically less available during the winter, so there may be an inherent preference for foods that are in season like starchier vegetables.
In addition, we have may have a genetic tendency to seek out more calorie-dense food in the winter months because food historically was scarcer.
Finally, a cool refreshing salad simply does not taste nearly as comforting as a hot bowl of soup on a cold winter day. The good news is there are lots of healthy substitutes that can still taste fantastic. Soups and stews are a terrific idea in the winter, as long as they are not cream-based or loaded with high-fat meat.
Both generally have a lower calorie density because they are higher in water than many foods. And you can sneak vegetables into a savory winter soup or stew if plain or raw vegetables don't appeal to you during the colder months.
If you crave potatoes, opt for sweet potatoes when you can to boost nutrition and satisfy your craving for starchy carbohydrates.
You can even top them with a little butter and brown sugar. Baked apples with cinnamon are a delicious fall dessert that you can top with a bit of yogurt or ice cream if you want to indulge.
Simple modifications like baking breaded chicken instead of frying, or replacing part of the sour cream or cream in recipes with Greek or low-fat yogurt can help you satisfy cravings without piling on the pounds when the weather gets cold.
Experiment with baked goods if you crave them during the winter -- try substituting a portion of the flour with whole-grain flour and a portion of the butter or oil with applesauce or canned pumpkin (a great way to boost nutrients, too).
And don't forget -- exercising at home with videos or at the gym, or engaging in active outdoor activities when you can during the colder winter months can both burn calories and boost your mood.