Please choose the correct ending to complete the given sentence: Health: [header] How to gain weight fast (for men ) [title] Eat more than three meals a day. [step] If you naturally have a really fast metabolism, eating three meals a day, no matter what's in them, isn't going to help you bulk up. Your body burns calories fast, so you need to feed it more than it can use up right away.

Ending1: As a result, you'll be building muscle more quickly. Keep eating, and if you're tall, you want to work on longer portions. Ending2: Studies have shown that women who eat three meals a day tend to lose an extra two pounds. Look for the food groups that it recommends when dining out. Ending3: That means eating not just when you're hungry, but throughout the day. Aim to eat five meals a day to gain weight. Ending4: To lose weight fast, build muscle through aerobic exercise. [substeps] If you can, get your legs, arms, and back toned.

Answer format: ending1/ending2/ending3/ending4