Do You Really Stop Losing Weight When You Eat Too Little?
The Truth About Starvation Mode
You find the motivation to lose weight and start a new diet; keto, intermittent fasting, flexible dieting, the method doesn’t matter so much as your determination to do it.
You calculate your calories, write your shopping list, plan your meals and clear the kitchen of anything that could lead you astray.
You download MyFitnessPal and hit up your ‘fit’ friend to get a copy of the workout they’re following.
You begin to weigh yourself daily and at the end of the first week, you’re 5 lbs down and feeling pretty pleased with how things are going.
The next couple of weeks pass and you’re still losing weight, albeit not as much as in the first week, but still, the pounds are coming off.
Fast forward to the 3-month mark and you’ve been following an alternating pattern of stalled weight loss and lowering your calories, only for it to slow and stall again.
By this point, your weight is hovering and the idea of whether or not you’re in starvation mode creeps in. Two more weeks pass and even though you feel like you’re doing everything right you actually gain weight.
It doesn’t make sense unless of course, you’re in starvation mode.
What is Starvation Mode?
There are 2 definitions of starvation mode; the scientific one and the bullshit one. Let’s do the bullshit one first, as this is what most people believe.
“Eating in a calorie deficit for too long will cause your metabolism to slow down so much that it will prevent weight loss and start to cause weight gain.”
I’m not sure where this idea of starvation mode first originated but whatever its origins it has since become a scapegoat for anyone struggling to lose weight.
The truth is, whilst dieting your weight loss can stall or stop altogether for a number of reasons but starvation mode isn’t one of them.
This is supported by the scientific definition of starvation mode.
“A state in which the body responds to prolonged periods of low energy intake [by burning] free fatty acids from body fat stores, along with small amounts of muscle tissue to provide required glucose for the brain.” (1)
So, the complete opposite of what you would expect to happen if you believe the bullshit definition.
Instead, of your weight loss stopping, it continues regardless of the duration or severity of your calorie deficit even if that means using muscle mass for fuel in the absence of fat stores.
“After prolonged periods of starvation, the body has depleted its body fat and begins to burn primarily lean tissue and muscle as a fuel source.” (1)
This means if you stay in a prolonged calorie deficit you will continue to lose fat before burning muscle mass when there is no more fat to burn.
It doesn’t halt fat loss or cause weight gain and instead will continue to break down either fat or muscle to create energy until there is nothing left to use.
This means for the average person who is trying to lose weight the starvation response is completely irrelevant for a few reasons:
- Weight loss should be achieved using a moderate to a small calorie deficit that encourages fat loss whilst sparing muscle mass
- You should be doing regular strength training to help with the retention of muscle mass when in a calorie deficit
- For the average person, it’s extremely rare to have the goal of reducing body fat so low that you also need to burn muscle mass for fuel
- All of the above means you will not be in a calorie deficit long enough to suffer from true starvation mode, making it essentially a non-issue
Perhaps the most well-known illustration can be seen in the results of a study conducted by Dr. Ancel Keys, aptly titled the Minnesota Starvation Experiment.
The Minnesota Starvation Experiment
In November of 1944, as World War II raged, a total of 36 men were escorted to their new home, in the quiet hallways of the University of Minnesota Football stadium as they had a different role play.
Each of the 36 participants had volunteered to participate in a starvation experiment conducted by Dr. Ancel Keys and his team (2).
From a pool of 200 applicants these 36 men had been carefully selected for their predisposition to bond well with others in difficult circumstances as well as their good physical and mental health.
Whether they truly understood what they would go through, it would become clear that they would undergo extreme physical and mental hardship in order to better understand the effects of hunger and starvation.
60 years later the words of Samuel Legg (6) would highlight the mentally and physical toll the participants were subjected to:
“I was walking along … [with my] buddy … it was deep into the semi-starvation, and we were tired … we would look for driveways when we got to a cross street … so we wouldn’t have to walk up one step to get from the road to the sidewalk …
We were tired and weak. And so, we were standing at a corner waiting for a light or something, and a kid came along on a bicycle, and he was really moving, pumping away … And I looked at him and said, “Wow, look at that boy. He’s really whizzing.”
And then I said to myself, “I know where he’s going. He’s going home for supper. And I’m not.”
And then for a very brief, I hope it was brief, moment … I suddenly hated the boy … I hate at this point to tell you this, because it doesn’t speak very well for me. But I remember … with … horror that I could feel such a thing. So utterly irrational, but there it was.
And you ask an experience that I remember; I sure remember that. That was rough.”
The purpose of this study by Dr. Keys was not to torture his participants but to explore the physical and psychological effects of semi-starvation as well as the most effective method of recovery and rehabilitation from starvation.
To do this they required all of the men to lose 25% of their body weight, and they set out to achieve this is 4 phases:
- 3 months of eating a daily calorie intake of 3,200
- 6 months of a semi-starvation diet consisting of 1,570 calories per day*
- 3 months of restricted rehabilitation where they ate 2,000–3,200 per day
- 8 weeks of unrestricted rehabilitation where there were no limits on calories**
*Several participants were kicked out of the study for cheating on their diet.
**Only 12 of the 36 stayed on for the non-compulsory 4th phase. During this period of unrestricted eating, they often consumed 5,000 calories a day with one participant eating 11,500 calories in one day.
During the entirety of the study, participants were required to walk 3 miles a day as well as work in the lab for 15 hours week and participate in educational activities for 25 hours a week.
What Did They Find?
Ancel and his team found that subjecting the men to semi-starvation caused most of them to suffer from some degree of emotional distress and depression.
They also observed that all men lost their interest in sex, became obsessed over meal times and would get irritated if meals were not served on time.
However, most importantly to our discussion, they found that although all men suffered a marked decline in basal metabolic rate during phase 2 they all lost weight and continued to lose weight for the duration of this phase.
This effect was so great that all participants kept on losing weight reaching as low as 5% body and the point where they could no longer lose any more weight without risking serious health problems (3).
These findings are in stark contrast with the erroneous view most people have of starvation mode, which if correct would have seen participant lose some weight before plateauing or even gaining weight during phase 2 of the study.
All this begs the question “why do people think they’re in starvation mode?”
Why Do People Think They’re in Starvation Mode?
As we discussed at the beginning of this article, the primary reason is a fundamental misunderstanding of what it means to be in starvation mode.
Whether this is a self-defence mechanism or a well-entrenched fitness myth that continues to pervade the consciousness of dieters is hard to say.
In reality, it’s probably a mix of the two.
Starvation mode, the bullshit definition, provides a convenient scapegoat for failed fat loss attempts.
It gives you a fundamental physiological response to dieting that you can blame for the reason you’re not losing weight instead of having to face up to the the real mental and physical issues that are really to blame.
In essence, it’s easier to say “I’m failing because of something I cannot control” than it is to say “I’m failing because I’m making mistakes” and then learning how to fix them.
Yet, it’s the latter that will lead to long-term sustainable weight loss.
Why Does Weight Loss Stop or Slow Down?
If it’s not the result of starvation mode, why is it that some people noticed a distinct slow down in weight loss, often followed by a complete stall and then weight gain?
Firstly, we must accept that to lose weight you must be in a calorie deficit. This is non-negotiable, if there’s no calorie deficit, then there’s no weight loss.
Most people are on board with this, at least initially, as they set their calorie deficit and begin losing weight.
However, over time there are a number of hormonal and metabolic changes that occur in response to weight loss. It’s these changes that can cause weight loss to slow down or stop altogether.
These changes are:
- Reduction in NEAT: this is the reduction in daily calories burnt from all activity that isn’t sleeping, eating or sports-like activity and includes walking to work, opting to use the stairs, fidgeting, working the garden, typing and more
- Hormonal changes: in particular the hormones Leptin and Ghrelin are affected which results in an increase in feelings of hunger and reduction in feelings of fullness after eating
- Change in total body weight: as you lose weight your overall calorie needs as reduced as you have less body mass to sustain
- Adaptive thermogenesis: this is the reduction of your metabolic rate in response to the severity and duration of your calorie deficit above and beyond what is expected due to the change in behaviour, hormones and total body weight (5).
It is the effect of these changes that are regularly mistaken for starvation mode.
When in fact what’s really happening is your calorie needs are reducing over time which causes your calorie deficit to slowly become smaller and smaller until it either becomes your calorie maintenance or even calorie surplus.
Combine this with typical dieting mishaps and misunderstandings and it’s easy to see how you can think you’re in a calorie deficit and not losing weight.
- Underestimating how many calories you’ve eaten
- Overestimating how many calories you’ve burnt through exercise
- Not accurately tracking your food intake
- The non-linear results of weight loss
- Incorrectly tracking your progress or not tracking at all
When this happens and you think you’re in a calorie deficit it can seem logical to reach for starvation mode as the reason you’re no longer losing weight but the simple reality is, you’re no longer in a calorie deficit.
Fix this and weight loss will resume.
Perhaps Most The Most Interesting Part…
Almost 60 years after the Minnesota Experiment, 19 of the 36 original participants were still alive and 18 were interviewed in an oral history project conducted from July 2003 through February 2004.
A letter was sent to each participant, inviting him to take part in a tape-recorded, structured interview. After oral consent was obtained, 14 participants were interviewed in their homes or offices, and 4 were interviewed by telephone.
Perhaps most interesting of all is that all things considered…
“the participants agreed that if the clocks were turned back, they would again make the same decision to participate, even after having experienced the physical sacrifice required.”
