The idea is to consume foods that will leave you feeling satisfied for long periods of time, foods that will not wreak havoc on your blood sugar and insulin responses. To do this stick to healthy fats for snacks, such as almonds for example. Most of the time people turn to sugary carbs or fruits that cause spikes in your blood sugar, leaving them satisfied for only a limited time. Once that spike in blood sugar comes back down it may "crash", leaving that person tired or hungry again. Another suggestion would be to make sure that you always have a chilled bottle of water with you wherever you go. Many times people allow themselves to become dehydrated, which then results in that individual feeling as though they are hungry. When in all actuality they may actually just be thirsty. Snacks work best when spread out evenly between actual meals throughout the course of the day. Hope I helped in some way.