My BMI is 16.5-17.5. I can't seem to get it higher unless I eat unhealthy but even then I lose it quickly. Any suggestions?

"My BMI is 16.5-17.5. I can't seem to get it higher unless I eat unhealthy but even then I lose it quickly. Any suggestions?"

Your BMI is not unhealthy where it's at now. However the only way I can come up with that MIGHT help, as a suggestion, is a calorie increase. However look for foods that are high in protein, and has the healthy fats and oils. Some good sources are oily fish, such as jack mackerel, salmon, sardines, Cheese and other dairy products can also help to add weight on. However when you add it, you want to do so slowly, It will be healthier that way. But up the calorie intake slowly until you start to see weight gain.

Talk to a doctor first to rule out the possibility that this can be from an underlying medical condition. After that, you might want to talk to a nutritionist.

Sounds to me though that you're eating habits are poor. If you're trying to gain and not gaining, then you aren't eating as much as you think or not as consistently as you need to. You could be stuffing yourself when you eat, but if you don't eat frequently, then you still might not be eating as much as you need.

You don't need to eat unhealthy to gain weight. Just increase the calories from healthy food. Use an online calorie calculator and get an estimate of how many calories your body needs. Then add 500 to that and see from there.

MyFitnessPal is great for tracking your food

Stress the complex carbs. If you eat unhealthy or utilize too many simple sugars and fats, you will get fat much quicker.

Good foods to utilize: Whole Milk, oats, rice, pasta, bread, peanut butter, extra virgin olive oil. Plenty of other goodies, those are just some of the basics.