Back then she could eat an 1800 calorie diet just like anybody else. Today she can gain weight on a 1300 calorie diet!
People use varying amounts of calories based on muscle mass and activity.
The metabolic rate drops with age, but the difference in the number of calories used is more dependent on activity.
The idea that the body learns to defeat diets, is, I believe, an urban myth.
You can work it out here:
http://www.bmi-calculator.net/bmr-calculator/
If you haven't done it before you may be surprised how few calories you need.
Once you've got the basic amount, you can calculate your daily calorie requirements using the Harris Benedict Formula
To determine your total daily calorie needs, multiply your BMR by the appropriate activity factor, as follows:
Code:
If you are sedentary (little or no exercise) : Calorie-Calculation = BMR x 1.2
If you are lightly active (light exercise/sports 1-3 days/week) : Calorie-Calculation = BMR x 1.375
If you are moderatetely active (moderate exercise/sports 3-5 days/week) : Calorie-Calculation = BMR x 1.55
If you are very active (hard exercise/sports 6-7 days a week) : Calorie-Calculation = BMR x 1.725
If you are extra active (very hard exercise/sports & physical job or 2x training) : Calorie-Calculation = BMR x 1.9
So lets say a woman was 65 years old, 5 ft 4ins tall, and 140lbs.
BMR would be 1273 calories.
and if she was sedentary multiply by 1.2
=1527
1527 Calories. That wouldn't take much eating.
Especially if you enjoyed food, and had an unlimited supply of it.
And if you had a strong appetite, every meal would have to be chosen with care, every day.
Another myth is that overweight people are all gorging themselves at Macdonalds,
and throwing chicken bones over their shoulders like King Henry VIII.
Take the woman above. 1527 calories.
For Breakfast she has a bowl of cereal and a slice of toast. 350 calories.
Add enough milk for tea and coffee during the day, and she is up to 600 calories.
For lunch she has a couple of brown bread sandwiches with lots of low calorie salad. Oh and a packet of crisps. Now she is up to 1050 calories.
For the next 6 hours she has nothing to eat at all.
Then for dinner she uses up the meagre few calories she has left, to eat a chop, two potatoes, and some veg.
Now she is at her daily limit, and I forgot to give her any fruit to eat.
She's going to be fat and have scurvy too.
What is going to happen in the evening when she again becomes ravenously hungry?
Or fancies a glass or two of wine.