If you’ve ever hit a stumbling block with your diet before, I’m sure you’ve heard the line:
“Maybe you’re not eating enough to lose weight.”
On the surface this statement appears to defy logic, but it’s actually a pretty common belief in most gyms around the country – and today I’m going to show you why it’s complete bullshit.
Why It Isn’t True

The law of thermodynamics (calories in vs calories out) is governed by one simple rule; you must eat fewer calories than you burn.
With less fuel available, your body has no choice but to start shovelling its reserves of stored fuel into the fire to provide you with energy, and that’s what creates fat loss. This is the only mechanism by which we can lose weight, so the very idea that someone can not be eating enough to lose weight makes zero sense, right?
It’s like telling someone they’re gas tank isn’t empty enough to drive!
And that’s exactly why it’s bullshit.
However, in order to understand why this is such a widely believed piece of advice, we must go deeper.
Usually when a person is told that they’re not eating enough to lose weight, it’s because they’ve hit a stumbling block on their diet, causing them to believe that they’ve pushed their body into something known as starvation mode – a nightmarish physical state where the body believes it’s being starved and retaliates by hanging on to body fat at all costs, making it physically impossible for you to lose weight no matter what you do.
We’ve all felt like that on diets before, but that’s not what’s really happening here.
You see, starvation mode does not exist.
Heck, if it did exist, it would be the solution to world hunger. This was shown during a 1944 study from the University of Minnesota, which used some of the most extreme methodology we’ve ever seen. The researchers were looking at ways to feed hungry populations after the end of World War II, so they quite literally starved 36 participants (not joking) and put them on a three-hour exercise regimen each day for six fucking months.
Starvation mode never arrived – instead, participants lose about half of their body weight, and some nearly died. (1)

Before we move on, I’d like to address metabolic adaptation.
This is the process by which your body begins to slow down your metabolism during weight loss, causing fewer calories to be burned throughout the day (because you have less mass). Many people confuse this with starvation mode because, essentially, it makes weight loss harder. However, it’s not the same thing at all. Metabolic adaptation is perfectly normal (as you carry less weight, you expend fewer calories) and it’s nowhere near as restrictive as most people believe. (2, 3)
Science is conclusive in the notion that in order to lose weight we must eat fewer calories than we burn.
Humans are hard-wired this way, and there has never been any research depicting a person who is “not eating enough calories to lose weight” (not ever!). (4, 5, 6, 7)

So What’s The Real Problem Here?
The fact that beliefs like “starvation mode” are still popular in most gyms usually leads people away from the real culprit in these situations.
Instead of zoning in on the issue, they start believing that their body is working against them, or even worse, that they are “broken”.
But what’s REALLY happening is much more straightforward.
Every time someone says to me:
“Hey Russ, I’m eating 1000 calories per day and can’t lose weight!?!”
… it’s because their personal trainer (or fitness app) has given them an unsustainable meal plan.
Every. Single. Time.
(And considering I’ve worked in gyms for almost 20 years, that’s a LOT of people!)
As such, the client follows this unsustainable meal plan for the first few days of the week, before frustration kicks in, causing them to fall off track and over-eat at the weekend and throw their numbers out of sync.
See the red line below?
We have someone who believes they eat 1000 calories per day, only to discover they were really eating on track until Friday and then consuming 3000 calories over the weekend. This makes their daily average calories 1857, significantly higher than the thousand they thought they were eating.

Now a stubborn trainer could argue that this is simply a lack of self-discipline from the client by not sticking to the plan, and many do, but in my experience that’s not the case.
Instead, I’d suggest the preset calorie target is wrong!
In order to create a successful transformation you need a diet you can actually stick to. In the graph above the client is averaging 1857 calories per day, so for this person I recommend aiming around the 1500 mark and seeing how they respond. What usually happens is the person experiences better results because they don’t feel the need to go off plan as much, and let’s not forget that 1500, while seeming higher, is actually lower than what they’re currently eating (1857!).
So would I describe this situation as somebody who is “not eating enough to lose weight”…?
Nope!
The reason they weren’t losing weight is because they were eating TOO MUCH – they just didn’t know it. It’s more like they’re not eating enough to stay consistent. Research shows us that the best diet is the one you can stick to, so that’s how I’d correct the issue. (8)
I also recommend monitoring your intake with a top app like Carbon Diet Coach, because as I always say, “If you don’t track, you don’t know.”

References:
- Keys A., et al. The Biology of Human Starvation. Civilian Public Service (1944).
- Camps S., et al. Weight loss, weight maintenance, and adaptive thermogenesis. Am J Clin Nutr (2013).
- Zinchenko A, et al. Metabolic Damage: do Negative Metabolic Adaptations During Underfeeding Persist After Refeeding in Non-Obese Populations? Medical Research Archives (2016).
- Howell S., et al. “Calories in, calories out” and macronutrient intake: the hope, hype, and science of calories. Am J Physiol Endocrinol Metab (2017).
- Leibel R.L., et al. Energy intake required to maintain body weight is not affected by wide variation in diet composition . Am J Clin Nutr (1992).
- Golay A., et al. Similar weight loss with low- or high-carbohydrate diets. Am J Clin Nutr (1996).
- Golay A., et al. Weight-loss with low or high carbohydrate diet. Int J Obes Relat Metab Disord (1996).
- Stewart T. M., et al. Rigid vs. flexible dieting: association with eating disorder symptoms in nonobese women. Appetite (2002).
Who Is Russ Howe PTI?

Russ has been a personal trainer in the UK since 2002, and provided both training advice and full programs on this website since 2011.
His work has been featured in Men’s Fitness magazine, and the content on this website led to him being voted one of the world’s top 50 fat loss coaches by HuffPost.
Russ spends his time coaching men and women inside the legendary Powerhouse Gym, South Shields, and writing training tips for the 114,301 members of his popular free training e-mail (join it below).
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