Why Eating Too Few of Calories Hurts Your Efforts at Weight Loss Part Two

By: Kyle Kamp, RDN, LD of Valley to Peak Nutrition

If you've Googled, "Why am I not losing weight?" at any point in your life, you've likely been met with countless pages of people voluntarily dishing out their opinion on what your next move should be to get the needle on that forsaken scale moving again.

In your research, it's highly likely you've read the line, "You have to increase your calorie intake to lose weight!"   What a misleading statement! Suggesting this would be akin to saying, "To get to your destination quicker, you just have to drive faster!"  No one mentions to you that your destination will include gravel roads, turns, bridges, stop signs, a 25-minute delay while a herd of elk crosses the road, and five stops so the family can empty the grande mocha frappuccino they begged you to pick up before leaving town.

The Big Three

The weight loss conundrum can be incredibly confusing, but it doesn't have to be.  There are a number of things that affect how many calories you burn, but there are three major things we've learned happen when a person reduces their calories in an effort to lose weight that can make continued weight loss even more difficult.  This is particularly true when people significantly reduce their calorie intake below what's needed.  They are:

  1. Their BMR drops…I'll explain.
  2. Some chemicals in the body change.
  3. Your NEAT also drops….I'll explain this too.

B M, What?

BMR.  It's a lot easier to explain the inability to lose weight to a person when they think BMR means "Big Mac Ready," but that's not it.  BMR is an acronym for "Basal Metabolic Rate"; basal meaning "basement" or "low" and metabolic rate simply meaning the speed at which you burn calories.

Make it easy for me: BMR is the fewest amount of calories your body needs if it were to simply exist laying in a bed all day long.

When you reduce your calorie intake to very low levels, the amount of calories you burn to keep your organs functioning also drops in an effort to keep you alive longer.  Think about it; if your body kept burning calories at a very rapid rate without you putting any more in, it would burn through the limited amount you're giving it in no time at all.  To keep you alive, it drops the number needed to stay alive down so it doesn't burn through the limited amount you're giving it.

Pesky Chemicals

The body is an incredible machine constantly readjusting itself to keep you alive, even in weight loss as it adjusts to functioning on fewer calories.  A part of this relearning process and getting used to its new, lower intake from you means there will be some chemicals that get thrown off in the process.  I won't delve deep into what they are or why it happens, but there are a few key chemicals affected:

  • The hormone that controls when you're hungry and full gets thrown off.
  • The hormone tied to stress gets off kilter.
  • The chief hormone responsible for the control room of your metabolism can also go awry.

This isn't always as dark and detrimental as it sounds, but it is a key part of why weight loss is so darn hard.

N-E-A-T- NEAT!

It sounds like the start of a catchy cheer you learned back in high school; doesn't it?  It's not though.  Instead, it's another really big word with a basic explanation.  NEAT is an acronym for Non-Exercise Activity Thermogenesis;  Non-Exercise meaning every hour you spend awake, but aren't intentionally at the gym, on the mountain, or doing some sort of planned exercise, Thermo- meaning heat,  and genesis meaning the generation of.  Put it all together and we have the amount of heat your body burns doing an activity outside of planned exercise, or more simply put, the number of calories your body burns outside of the gym (or other planned exercise).  This includes a variety of different things like taking the stairs, walking to and from your office, and annoying your office mate with drum cadences played on your desk.

Enough of that; here's the part you care about: this number, like BMR, also goes down when you restrict calories.

Still Confused?

There is a very important distinction to make here as well that I feel often gets overlooked.  When looking at whether or not a large calorie deficit is the culprit behind why you’re struggling to continue weight loss, you have to compare yourself only to yourself.  Your metabolism is incredibly unique and made of many different parts, so to suggest that you should begin to see weight loss simply because John, two cubicles over, ate 1300 calories and still lost weight would be a significant error.  You have to compare yourself to yourself, which is exactly why we compare the same Steve below to show how reducing your calories too much can affect your efforts; pay particularly close attention to how much variance there is between how many calories the two are eating and the consequence it plays in the total calorie burn:

Smart Steve at 270lbs

Zealous Steve at 270lbs

Eating

2300kcal/day

900kcal/day

Calories needed just to lay in bed (BMR)

1500kcal

500kcal

Calories burned going to the grocery, walking to and fro, and playing a desk-based drum cadence (NEAT)

300kcal

75kcal

Hormones and chemicals

Off-kilter

Way more off-kilter

Total calorie "burn"

1800kcal

575kcal

(It should be noted that this doesn't paint the entire picture, nor is it intended to.  It's meant to paint a very basic picture as to why eating less can sabotage your efforts. We've accomplished our goal if it does that…health gurus, be mad if you must.)

Look at that difference!  This difference, more than 1200kcal in our example, can mean the difference between inability to lose weight and weight loss success.  There are many more factors that play into how many calories a person burns on a daily basis (hence why the math doesn't play out in our example), but this is the bulk of it and meant to give you a good idea as to why eating too few calories can hurt your effort at weight loss.

Putting It All Together

Together, this collection of mish-mash that happens day-in and day-out without you knowing makes weight loss very difficult.  The greater the calorie deficit, the greater the extent to which these things happen, the harder it is to lose weight, and the more discouraged you become; and who can blame you?

Part three will delve into the "Okay, then what?" piece of the low-calorie intake and lack of weight loss equation.  There is no way to avoid this cascade of woe, but there is a way to reduce the impact and make weight loss a real possibility.


Valley to Peak Nutrition is a nutrition company whose aim is  to help you get it done in the backcountry.  All services are provided by Registered Dietitians and offer coaching, accountability, and custom nutrition plans built to help you accomplish your goals.  Their work is based in science, research, and has been proven to enhance the performance of everyone from mountain-based athletes to weekend warriors.