How Much Should You Eat?
Last week I explained why you shouldn't ever drop your calorie intake too low, despite what many popular diet programs will tell you. If you missed it, go back and read it here.
We hear so much about "Calories In vs. Calories Out," and many people think that eating as little as possible is "good." I mean, if the principle is "Eat Less, More More," then eating almost nothing and working out all the time must be really good, right?
First, let's talk energy balance.
What you need to know:
- Calories refer to units of energy.
- Energy cannot be created or destroyed, only transferred.
Energy balance means the energy going out = energy coming in.
When there is energy balance, the body is properly fueled, and everything's running as it should be.
When there is an energy surplus, the energy can be used for things like rebuilding muscles, refueling, or generating heat, or it can be stored as fat. If there is a lot of extra energy coming in vs. what is being expended, that causes fat gain.
When there is an energy deficit, the body uses stored energy to fuel activity and bodily processes BUT as we discussed last week, if this occurs for too long, the body will need to adjust, slowing down metabolism and other processes so there's enough energy to sustain life.
If you take a look at the chart, you'll notice that the BIGGEST chunk of energy expenditure aka calorie burn comes from Basal Metabolic Rate, which is the amount of energy needed just to live.
Using one of the examples from last week, if you're a 40-year-old woman, who's 5'6" and 160 lbs, your BMR is roughly in the neighborhood of 1474 calories per day. That means if you laid in bed not eating or moving, you would still be expending 1474 calories per day.
Consistently restricting calorie intake below BMR requires the body to make adjustments so it needs less energy and less fuel. It's like pinching pennies to get by when money is tight.
When a person's metabolism downshifts or "slows down" to adjust, it doesn't mean your metabolism is "broken." It's actually working the way it's supposed to, which is doing whatever the heck it takes to keep you alive.
No matter what your health and fitness goals are, you need to eat more than your BMR. Period. No excuses.
This doesn't mean you're going to gain fat or weight!
BMR makes up the majority of your daily expenditure, 60-70%. Eating, chewing, digesting, and absorbing food requires more energy on top of that. So does getting out of bed, getting dressed, making coffee, getting the kids dressed, driving to work, etc.
Notice I haven't even mentioned exercise yet...
Intentional physical activity, or exercise, makes up the smallest portion of daily calorie burn for most people. Even if you don't work out very often or very intensely, you'll still need more than a 1200 or 1400 calorie diet.
Using the same example of a 5'6", 160 lb woman, if BMR is roughly 1474 calories and it's only 60-70% of the daily expenditure, she'd probably need to be eating more than 2200 calories/day before she'd get into a surplus. (Again, this is just an example and each person's exact number will be different based on lean muscle mass, stress levels, sleep deficit, genetics, and more, but the same principles hold true!)
If you are exercising regularly but also following a diet that doesn't provide your body with adequate fuel, it's very common to feel like you're working your butt off and not getting results. The answer is usually not to eat even less and exercise even more; it's likely that you might need to evaluate your nutritional intake and make sure you're getting enough to support your calorie needs, including training and recovery.
It's totally normal to be concerned about increasing food intake after decades of dieting and being told to just "eat less." One way to eat enough to support your BMR but not too much to cause fat storage is to move more, and I don't mean doubling up on workouts at the gym.
Our non-exercise physical activity has a much greater effect on our Total Daily Energy Expenditure than working out will, yet we've become incredibly sedentary thanks to modern technology. Try moving more throughout the day. Get up from your desk. Get up from your computer. Don't sit on the couch for hours at night without moving. Park further away if it's safe to do so. Take the stairs.
And if your body feels too fatigued to do any of that stuff? Idk, maybe you need more fuel.
