The calorie content of your diet is the most important factor as to whether you lose, gain or maintain weight. An excess of calories results in weight gain; a deficit leads to a loss, while balancing your calories causes you to maintain weight. Once you've worked out how many calories you need to consume to meet your goals, the next step is to consider the distribution of these calories in your meal plan.
Macronutrients are protein, carbohydrate and fat -- the three nutrients where calories originate. You need all three for a healthy diet, but they need to be in the right balance. Del Helms, associate professor of health science at Mt. San Jacinto College, suggests that you aim to get approximately 45 to 65 percent of your calories from carbs, 20 to 35 percent of your calories from fat, and 15 percent from protein. If you're more concerned with losing fat, however, sports nutritionist Dr. John Berardi says that you instead aim for 40 percent carbs, 30 percent fat and 30 percent protein. Generally, the more active you are, the higher your calorie intake should be, and men require more calories than women. More active people may also need more carbohydrates for energy and recovery. One other factor to consider is fiber. Fiber is a carbohydrate, and important for health; women need 25 grams per day while men need 38 grams.
Splitting the Calories
Probably the simplest way to distribute your daily calorie intake is to divide it evenly between meals. If you're eating 1,500 calories per day, for instance, and want to eat three meals per day, 500 in the morning, 500 at lunch and 500 in the evening. If you'd rather have three meals and a couple of snacks, consume one-quarter of your total intake at each meal and the final quarter split between snacks.
Managing Each Meal
To stay as accurate as possible with your calorie distribution, you need to count up how many calories are in the foods you're eating, either by looking at packaging or checking calorie-counting websites, or on the websites of the food manufacturers. Alternatively, Dr. Berardi suggests a simpler method, using your hands to gauge serving sizes. For those adhering to his 40 percent carb, 30 percent protein, 30 percent fat macronutrient ratio, Dr. Berardi recommends men eat two palms-worth of lean protein, two fists-worth of vegetables, two cupped handfuls of starchy carbs and two thumb-sized servings of fat at each meal. Women halve these amounts.
The Keys to Individualization
The most critical factor in a meal plan's success is that it gives you the results you want and is relatively easy to follow. Therefore, if you actually prefer to eat a bigger breakfast to fill up, a smaller lunch because you're busy, and a moderate dinner, you can. Similarly, if you're always rushed in the mornings, then a small breakfast and slightly larger lunch and dinner may work better. The key is to find what works best for you.