What can I do to earn more calories?

Terminology. We do not "earn" calories, but consume foods that provide calories. In nutrition a calorie is the amount of heat needed to raise the temperature of 1.0 kg of water by one degree celsius. One gm of protein or sugar has about 4.0 calories and one gm of fat has 9.0. One gm of alcohol has 7.0 calories. You can choose how you get your calories, but a balanced diet is good for you.