For 30 pounds you would need to deficit of about 1,750 calories per day, which is very unhealthy and unrealistic target. A pound equals to about 3,500 calories. A deficit of 500 to 1,000 calories per day to lose 1 to 2 pounds per week is more reasonable but would take longer. You would be losing 4 to 8 pounds per month although it’s longer it losing 30 pounds will happen. Men should also eat no fewer than 1,500 calories a day and women should eat at least 1,200 calories a day.
For 40 pounds you would need to eat 1,200-1,400 calories in one day. This means 350 to 450 calories in each meal and a 100 calorie (no more) snack.
I hope this helps!
