To gain weight, you should consume 1600 calories a day. Each one of your meals should be about 400 calories and you can snack on a total of 400 calories a day. If you prefer, have 430 to 435 calories for each meal and keep your snack total to 300 calories – whatever works best for you. We have different calorie plans for women, depending on your needs. Pregnant and breastfeeding women should aim for 1700 calories a day – 12WBT has a pregnancy plan just for you.