All meals are important, but breakfast is what helps you start your day on the right track. The best, heartiest breakfasts are ones that will fill you up, keep you satisfied, and stave off cravings later in the day. Aim to eat anywhere between 400 and 500 calories for your morning meal, and make sure you're including a source of lean protein plus filling fat (e.g., eggs, unsweetened Greek yogurt, nuts, or nut butters) and fiber (veggies, fruit, or 100% whole grains). Starting your day with a blood sugar-stabilizing blend of nutrients will help you slim down without sacrifice.
Here's something else most people probably don't know: Fidgeting is good for you. It's considered a nonexercise physical activity, and it's an important way to burn energy. You get more health benefits if, in addition to exercising, you are a more fidgety, more active person the rest of the day. This means gesturing while you're talking, tapping your foot, just moving around.