Pretty much just repeating what the other posters said! It's a lot better for you and your body if you use the calories on healthier food. You can get a lot of fruit for the amount of calories in a chocolate bar! For example, some chocolate bars can be around 170 cals. Four medium strawberries can be only 15 cals!
Aim for a high fibre breakfast too to keep you satisfied for longer until lunch. If you need a mid morning snack, a piece of fruit or some nuts would be fine. I currently try to have my 3 meals, morning snack and an afternoon snack but if I have a high fibre breakfast (as my CC app will tell me) then I find I don't need the mid morning snack.
Hope it goes well