Worried about your lack of appetite? The weather, stress, or certain medications can make you less hungry. Here's when you should be concerned.Meals can be motivating. Raise your hand if you’re one of the many people who get through long work days by day-dreaming about your next meal.

But some days, you just can’t muster up the hunger to eat even your favorite meal. Why is it that on some days you feel like you could eat another lunch and then some days you can barely make it through half a lunch? Does a lack of appetite signal that something else is up with your body? Or is it completely normal?

Well, that depends on a whole host of factors.

At the very least loss of appetite is harmless. Maybe you just had a busy morning and you forgot to eat lunch until, um, 2:00 p.m. Or maybe you had a huge lunch and sitting down to another full meal doesn’t sound all that exciting. These types of brain-belly disconnects are common.

But then there’ the opposite end of the concern specrum.