Probably, men are less concerned about calories than women.
A lot of women who have surgery have done just about all the diets out there, and so have at one point or another, have calories drilled into their brains.
Being concerned about calories is probably more about what makes you feel safe and comfortable, than what the numbers themselves actually mean.
That said.
When patients need to be instructed about food intake, the base guideline is how many calories for that person, then, how to balance that out between the 3 major nutrients, protein, carbohydrates and fat.
1) This program is individual, in other words, unique to the needs of the person.
2) It is determined by the body frame of the person, what conditions they need to control, and what their daily activities are.
Then
3) If you do not have a medical issue that is best taken care of by losing weight first, then the calories will be calculated to maintain your present weight.
4) If you have medical issues, you wil be instructed to a) change the balance of your food intake by limiting the intake of certain types of food, and, b) if you need to lose weight, then will be instructed for weight loss by limiting the total intake as well.
The determining factor of preferable body frame with medical issues where body weight plays a part is your height.
In other words, the taller you are, you will be expected to be heavier, the shorter you are, you will be expected to be lighter.
Let's translate this into BMI-body mass index, which indicates the balance of your body frame. 22 is considered the median. A 5 foot person will have a BMI of 22 when he/she is just over 112 lbs. A 6 foot person will have a BMI of 22 when he/she is 162 lbs.
The amount of calories you expend is calculated from your weight, with your age and gender are taken into consideration.
FYI: one equation that is often used. (Please note, the unit is metric, so you need to do some conversion for inches and lbs)
Harris-Benedict Equation for REE (Resting Energy Expenditure)
Male: REE=666+(13.7 x weight in kg)+(5 x height in cm) - (6.8x age in years)
Female: REE=655+(9.5 x weight in kg) + (1.8 x height in cm) - (4.7 x age in years)
To this, the total calories of the person's daily activities are added. For instance, if you walk at a fast clip for 30 minutes, add 100 kcals, house work for 30 minutes, add 80kcals, etc.
The total of all your activities and REE is your daily expenditure.
To lost weight the conventional way, you subract 500 to 1000 kcals from this total.
To maintain your weight, your intake should equal this.
So.... I probably lost you somewhere along the way