Do you need a calorie reduction to lose weight?

Last week I was watching a video where a nutrition coach was describing why dieting and simply cutting calories does not work for weight loss. I was hooked from that (completely wrong) statement and figured, “what the heck, I’ll invest 5 minutes to see what else they come up with”.

This coach went on to describe how cutting calories caused your body to “react” and want to hold onto fat. What I find troublesome about descriptions like this are that there are some truths hidden in the talking points but it’s hazed over with a lot of misinformation.

In my experience some people actually will see progress following advice from coaches like this because they’ll make better food choices and subsequently lower calories (even if they aren’t aware they did) and others will choose different foods, still follow the rules but never make a calorie reduction. So the latter person actually followed the advice more strictly (not lowering calories) but the results of that are usually…no weight loss.

Of course if you are a rote beginner, coming back from a long training layoff or have never followed a true nutrition and training program, you can recomp pretty well. Research sees this all the time in subjects who simply start weight training without making a calorie reduction and lose fat while gaining muscle. If you hover around maintenance and train really hard, some people can still recomp of course, it just takes much much longer. However, what is happening are probably daily fluctuations where at points you ARE in a slight deficit so you lose fat but are consuming adequate protein, so you retain or even gain muscle.

Presenting physiology as if your body is “reacting” or “freaking out” only damages people’s view of nutrition. Unless I’ve missed something, your physiology doesn’t have a unique personality in it’s hormones, cells and adaptations. There’s nothing for your physiology to have a personal and emotional reaction to. That doesn’t make any sense.

Instead we are comprised of a many faceted and complex system of tissue that has afferent and efferent signals as well as internal mechanisms that run many redundant systems. What does that mean? It means your body responds to environment (internal and external) and stress and makes subsequent adaptations.


Lets take the hormone insulin as an example. Derided by some, loved by others, misunderstood by many. Kind of like the Andy Kaufman of hormones.

For most lay-examples, we get the following equation:

Eat carbohydrates > glucose released into bloodstream > insulin released to direct storage > fat cells store excess glucose energy as fat

So if we jump to the conclusion most people do, we can make the equation even simpler:

Eat carbohydrates > store fat

Thankfully we are moving away from this theory/hypothesis and as the general public learns that protein also causes insulin release and oh yeah, high-fat over-feedings cause insulin resistance, they’re calling B.S on stuff like this.

Many coaches out there are not education themselves on physiology and thus remain in the dark ages of nutrition. Are they going to get some things right? Of course, but they’ll hurt as many people as they help and the people who do see success will have an almost impossible-to-reverse confirmation bias that what they did is the ONLY thing that can work for them.

Don’t be afraid of change

I’ve heard a few coaches say that if they look back on the programs they wrote 5-10 years ago, they’re embarrassed by what they were having people do.

That’s good.

If you never get better and educate yourself on something you do for a living, then you can always look back and confirm to yourself how right you’ve been from Day 1. That mentality is more problematic then I want to get into; instead as you learn you should change methods while trying to present the best possible information you can, based off the most up to date research and knowledge. Some underlying principles may never change and, funnily enough, some things come back full circle (so you WILL be right about some points) but the overall goal should be to keep refining, learning and getting better.

Lets take a brief look at what insulin does beyond simply directing excess energy to fat stores:

  • Signals the pancreas to lower glucagon (glucagon signals the liver to release glucose into the bloodstream)
  • Halts gluconeogenesis in the liver (essentially telling the liver to stop making new carbohydrates)
  • Signals glucose transporters in muscle tissue to pull glucose into the muscle
  • Signals fat cells to stop releasing fatty acids/glycerol into the bloodstream
  • Lowers protein breakdown (which has a permissive effect on muscle growth)
  • Lowers cortisol (this can have some stress reduction benefits)
  • In the presence of carbohydrates, can help keep Leptin higher

Some of this might sound good to you aka lowering protein breakdown and dampening cortisol. Some might sound negative aka signaling fat cells to stop releasing energy.

However when we take a look at Type II diabetes we actually see how important insulin is, as all the tissue involved above develop insulin resistance. In that case we end up with the liver making too much glycogen and releasing excess glucose into the blood, muscle tissue that won’t accept glucose (one of your best glucose disposal sites) and even your fat cells, which require insulin to keep them from flooding too many fatty acids into the bloodstream.

Many of the things we blame insulin for are actually key to our health and survival. In cases like Type II diabetes lowering carbohydrates is a viable strategy for regaining insulin sensitivity but so is lowering calories.

Back to calories…

Lets just accept that the truth is always more complicated than we realize but for us, on the user end, we really don’t have to try to “control” our hormones. Instead we have to control our environment, stress (including exercise), sleep and calorie intake. Essentially, we’re controlling all the input (food), some output (exercise) and then recovery.

To say that calorie control is not a part of that equation means all we have to do to lose body fat is exercise, sleep and control our environment. Sure, those are extremely important and helpful but the largest impact we can have on our weight is our calorie consumption.

Ready for a truth bomb? Some metabolic adaptations are unavoidable and expected.

You can do a veeeeeery slow recomp over months and months if you already have some decent muscle mass and not too much fat to lose. Beginners can jump on this bandwagon too. But for a huge portion of the population, calorie control is a must to lose weight, especially body fat.


The “freak out” your body was accused of? It’s really metabolic adaptation and it goes both ways. Not like THAT(wink). What I mean is that you see metabolic adaptations if you under-eat and over-eat.

Here’s the breakdown of how your body expends calories, lifted directly from Lyle Macdonald here, since it is such a great summary of Metabolic Rate:

Now the determinants of total metabolic rate are multi-fold, typically divided up into the following four categories:

  1. BMR: Basal metabolic rate (also called RMR or resting metabolic rate): this is just the basal processes to run your body.
  2. TEF: Thermic effect of food, the extra calories you burn from eating. Quick-estimated at 10% or so it actually depends on the nutrient eaten.
  3. TEE: Thermic effect of exercise. The calories burned through exercise.
  4. SPA/NEAT: Spontaneous physical activity/Non-Exercise Activity Thermogenesis: This is a newer category and separate from thermic effect of exercise, it’s the calories you burn moving around, fidgeting, changing postures. It happens to be massively individual.

It's very important that you take away that ALL of these components respond to how much you eat. They’ll go up if you eat more and down if you eat less, chronically.

So what’s changing that makes your metabolic rate drop?

Remember, we are adaptive organisms, if we change an input, we’ll have a change in output. Like it or not, this is your physiology and this is your reality.

  1. Bodyweight – Shouldn’t be a shocker here, if your body weight goes down, even if a lot of it is fat mass, your Basal Metabolic Rate will drop too. This is why people who weigh 130lbs don’t need to eat 3,000 calories per day to maintain their weight while people who weigh 200lbs do. That’s right, if you’re overweight, generally your BMR is HIGHER, not lower. This will slow by about a scaled % during a calorie reduction and weight reduction.

  1. Adaptive Component – This is an additional metabolic adaptation that cannot be explained by changes in bodyweight and is not scaled. Usually it accounts for around 5% or so of total metabolic rate drop. This is from a reduction in thyroid, leptin and neural drive.

  1. N.E.A.T – A described in the bullet points above. You might see a large (or small) change in non-exercise output from lowered calorie intakes. This is wildly different for many people and is largely genetic-based. Some people slash calories and feel such fatigue and lethargy that they simple stop moving unless it’s necessary. Others see this whey they overeat and see an increase in spontaneous activity. It’s largely subconscious and can make a huge portion of your energy output.

Don’t freak out!

So we have some real-deal stuff to combat when lowering calories to lose body fat. The metabolic adaptation components are unavoidable. If you permanently lose weight, your BMR will permanently drop simply because there’s less of YOU to move around. The adaptive components and N.E.A.T can be off-set by doing a few things:

  1. Not dropping calories too low, too soon – Huge drops in calorie reduction will cause large metabolic adaptations and a big drop in leptin. Leptin is a hormone released by fat cells to help keep you from starving. Having low levels drops your metabolic rate, makes you hungry, drops thyroid and testosterone and induces lethargy.

  1. Having some diet breaks or carbohydrate refeeds – Taking 48-72 hours off from long dieting, possible even a week sometimes can help restore leptin levels, refill muscle glycogen and reverse some of the metabolic adaptations. You simply go back to maintenance, enjoy the food and stress reduction, then resume dieting