Eating throughout the day, but under my calorie count?

Senabun

I try to eat throughout the day, but I end up really below the suggested calorie count.
On days I have school, this is what my typical food diary looks like:

Breakfast: Banana

Snack: Small bag of unsalted trail mix

Lunch: Apple, pear, and yogurt w /granola

Dinner: Cereal and/or brown rice with soy sauce and a few slices of Eckrich sausage

I usually don't snack after dinner because I feel full or too exhausted from school to care to eat anymore

I'm supposed to have at least 1600-1700 calories a day. I eat like this on days I have school which is every other day--these days are also the days I focus on weight training and cardio the most so I probably should be eating a bit more calories than what previously stated. On days I don't have school, I eat more meats, fish, and a select few of veggies if it's available in the house--my calories easily get to the amount of calories I should be eating on these days, if not a little bit over.

Bad habit?