When you lose weight, the numbers on the scale aren't the only things that change. Thermoregulation, or the modulation of body temperature, changes as your metabolism and body fat percentage shift. Put on an extra layer of clothing and drink a steaming cup of herbal tea to keep yourself warm and toasty.
The body of an overweight or obese person has a small surface area to volume ratio. Heat is held in the body and lost through the skin. Consequently, large people retain a warm body temperature easily, and heat dissipates across their skin slowly. Conversely, a thin person with a large surface area to volume ratio gains and loses heat rapidly. An overweight person also has a higher percentage of body fat -- an insulator -- which facilitates heat retention.
Diets that are extremely low in fat can cause a feeling of coldness, according to WellWVU, a wellness website of West Virginia University. While it's good to cut out fast food and potato chips, you shouldn't eliminate fat from your diet completely. Be sure to include healthy fats, such as olive oil, fatty fish, avocado and nuts, in your meal plans.
When to Worry
While some physical changes are a normal part of weight loss, a perpetual feeling of coldness combined with other symptoms could indicate an eating disorder. If you have an intense fear of weight gain and a distorted body image, and you find yourself practicing unhealthy habits such as prolonged, strenuous exercise, binging and purging or refusing to eat, talk to your doctor immediately.