By now most of us know that if you consume (eat) more calories than you burn (through exercise), you will gain weight. But did you know there are others way you could be gaining weight, even if you’re watching your calories? Here are some surprising causes of weight gain to consider.

1. Giving up caffeine

Caffeine acts as a stimulant, which lessens your appetite, and it also acts as a diuretic, so it makes you shed water. So if you stop drinking caffeinated coffee and colas, be prepared to be a little more hungry than usual… and possibly gain a little weight.

2. Food allergies

We all know that food allergies or sensitivities can give us breathing issues and migraines, but did you also know they can make you retain water, and even gather fat in weird places? True!

3. Prescription drugs

Birth control pills and NSAID pain relievers, as well as other prescription drugs, can cause weight gain as a side effect, so be prepared!

4. Quitting smoking

Everyone knows smoking is very unhealthy, but one reason a lot of people don’t want to quit is because they know if they do, they may gain a little weight.

5. Thyroid problems

Thyroid problems are one of the most common medical conditions that can cause weight gain. It’s very treatable, and very easy to detect, so if you have an issue with unexplained weight gain, you may want to raise the issue with your family doctor.