I must admit I'm a little torn about the question of snacking. I know there are numerous studies which purport that eating 5-6 small meals a day (perhaps 3 meals and 2 snacks) is ideal. The theory is that you're stoking the "fire" of your metabolism, burning more calories and body fat. But if you're consuming cheese and crackers, yogurt, pretzels and nuts (pretty typical), are you honestly able to control the quantity you consume? It's pretty easy to overeat unless you're extremely disciplined. It's dangerous! Look, 5 crackers and 1 oz of cheese total 170 calories. and 10 little almonds are 160 calories. So even if you limit yourself to a tiny controlled snack, two of these per day can contrbute significantly to your energy stores. In terms of energy balance it takes about an hour of running at a good clip to burn off 400 calories. And I'm not convinced that eating a snack or small meal (and then sitting around) is going to give us an equivalent boost in metabolism. Sorry!
Food for thought. Think about why you're snacking. Are you snacking because you're hungry or because you're bored? Hmmm. Listen to your hunger cues. Of course once we start thinking about food we almost always get that hungry feeling. Waiting 20 minutes is one strategy that has worked for several of my clients. Set a timer and start doing something distracting. Quite often the feeling of hunger is no longer there when the timer goes off.
If you're healthy and eating 3 well considered meals per day consisting of appropriate portions of protein, vegetables and healthy fat, I'm not sure snacking is necessary. You probably won't be hungry as your body will be receiving adequate nourishment. And I hate to break the news but your metabolic rate is not going to take a nose dive just because you haven't eaten anything in the past two hours. If we want our body to turn to our fat stores for energy, perhaps we should encourage it to do so.
But if you're starving and you do crave a snack, choose fruits and vegetables, lean protein and a small amount (like 10) of raw nuts. Bottom line. Do what works for you. If you're moving towards your goals, keep doing what your doing, whether it's frequent meals and snacks or not! However if you're not headed in the right direction then a tweak is in order. Maybe drop one or both of those snacks. Remember change only comes when you change what you're doing!