Final answer:
Drinking an extra 150 calories a month would result in approximately 0.51 pounds of weight gain per month.
Step-by-step explanation:
On average, a person needs 1500 to 2000 calories per day to sustain daily activities. If an excess of 200 calories per day is ingested, one extra pound of body weight will be gained every 18 days. So, if you drink an extra 150 calories per month, that would be equivalent to an extra 150 x 12 = 1800 calories per year. Since there are 3500 calories in one pound, this would lead to a weight gain of 1800/3500 = 0.51 pounds per year. Therefore, drinking an extra 150 calories a month would result in approximately 0.51 pounds of weight gain per month.