Ever have one of those days where you feel that you cannot get enough to eat? Ever wonder why? Sometimes, we know we are extra hungry because we did not eat much the day before or because we did more physical activity than usual. Other times, there appears to be no reason for it. One possible explanation has to do not so much with how much we ate but with what we ate the day before.

A study was recently published in the Journal of Clinical Investigation looking at the effects of different types of fat on appetite. Some mice were given palmitic fat for three days in a row. Palmitic fat is a saturated fat found in butter and beef. The rest of the mice were given oleic fat which is an unsaturated fat (healthier than saturated fat) normally found in nuts, olive oil and fish. After 3 days, the mice on the palmitic fat became resistant to the appetite suppressing hormones leptin and insulin. This means that the mice did not feel full and stop eating as early as they did before the palmitic fat. This led to increased calorie intake which will lead to weight gain if continued. Studies in humans have had similar results showing increased calorie intake the day after a fast food meal.

What to do? It would be easy to say, "don't eat saturated fats" but that is not always possible or desirable (ever have a craving for a cheeseburger and fries?). Now that we are aware of the effect of a high saturated fat meal, we can take steps to help prevent overeating.

• Keep this phenomena in mind and make a conscious effort to eat healthy the next day
• Do not let yourself become too hungry. Have a snack between meals.
• Start off the meal with a salad to help fill you up with minimal calories
• Eat slower than usual to allow your body the time to feel full.