I think a lot about the world we currently live in. I think about it more than I probably should if I’m being honest. I think about it a lot because the world is full of contradictions. Throughout history, many great works of literature have focused on contradictions that make up the human condition, just as many philosophers have spent their lives thinking about the same thing. We believe people should act one way, yet we act differently. We say we want to do one thing but find ourselves doing the opposite. In these contradictions, we get the phrase, “Actions speak louder than words, yet find ourselves doing the opposite. In these contradictions, we get the phrase, “Actions speak louder than words.”
However, one of the constant contradictions I think about is the information age. Specifically, we live in the most information-rich era of human history. The device you’re reading this blog on gives you access to more information than any of our great–grandparents could’ve ever imagined possible. And yet, despite access to all our information, we still find ourselves falling victim to pesky half-truths and myths.
Nowhere is that truer than in the world of nutrition. Entire books have been written on separating wheat from the chaff regarding nutrition fact. Part of the reason why nutrition myths can remain so prevalent often boils down to that annoying phrase: “It depends.”
And yet, despite all the books, courses, blogs, and educational material out there focusing on delivering sound and evidence-based nutrition advice, some nutrition myths find a way to stick around. One of those? The starvation mode myth.
What is Starvation Mode?
As commonly accepted, but widely misunderstood – starvation mode is thought to go something like this:
A person wants to lose substantial weight, so they crash diet of 900 calories a day for a few months. Early on in their crash diet, the scale is heading down, and they’re dropping body fat. At a certain point, that weight loss starts to slow down, and eventually stalls out completely. Or, in especially awful cases, that person who is drastically undereating at 900 calories a day might even start gaining weight back despite their incredibly low caloric intake, as a result of metabolic damage.
For quite a while, especially in the fitness and nutrition community, the prevailing wisdom around why this slowing down and stalling out happened came about thanks to a fancy-sounding theory called starvation mode. The idea behind starvation mode essentially says that because a human body has evolved over the course of thousands of years to look out for survival above all else, there’s a point where the body recognizes it’s being dieted down to a mortally dangerous point. So, it starts flipping switches and pulling levers to keep you from losing more weight in an effort to keep you alive.
Is Starvation Mode Real?
Is starvation mode real, and is that actually how the body operates?
From a physiological standpoint, starvation from chronic malnutrition, that is an overall inadequacy or lack of calories, is a real concern. At some point along this continuum, our body will move to break down all stored tissue within the body (fat and skeletal muscle) in an effort to support vital organs. Once these stores are felly depleted, the only next source of energy becomes visceral organ tissue – digestion comes to a halt as gastrointestinal function ceases, breathing and heart slow significantly, cognition becomes impaired, and neurons that conduct electrical transmission begin to fail and die off. After roughly 2-3 months without food, life can no longer be sustained.
Keeping in mind that true starvation is real – let’s go ahead and set the record straight about starvation mode as pertains to weight loss: In the presence of a caloric deficit, whether through eating less, moving more, or a combination of the two, weight loss is inevitable. This is based on the law of thermodynamics, as such, we simply cannot gain more body tissue when the raw materials (calories) are not available. When someone wants to lose weight and has a drastically low daily calorie intake for an extended period of time eats drastically fewer calories than their body needs on a daily basis for an extended period of time that does NOT then influence the body to start holding onto body fat in some sort of last-ditch effort to keep someone alive.
Now, that’s not to say that our bodies and brains don’t try to keep us alive, because they certainly do. They just don’t go about it thanks to some unknown and invisible force called starvation mode.
The body is undeniably smart and has plenty of tricks and unconscious ways that it can work to keep us alive when we’re getting deeper into a diet. It’s why we start to crave more calorically dense foods and it’s why hunger shows up more regularly. Those are signals that are being sent from the body and the brain to influence us to eat more. Because, from an evolutionary perspective, eating fewer calories than you need to survive for an extended period of time is a fast track to not being around for too much longer.
But just because the body has all kinds of ways to influence us to eat more when we’re on a diet does not mean that starvation mode is real. In fact, this has been studied.
There’s a famous study known as the Minnesota Starvation Experiment. The Minnesota Starvation Experiment has been written about extensively across the Internet and various publications for decades now, so I won’t rehash everything. But some important points uncovered in the study are worth mentioning:
- 36 men were put on a “starvation” diet over the course of 24 weeks. Those individuals started out eating 1,560 calories per day, and over the 24 weeks, their caloric intake was lowered to ensure that weight loss kept happening.
- Along with their calorie deficit, these men were expected to walk or run 22 miles every week.
- In the end, this meant that most of these individuals were consuming roughly 50% of their daily maintenance energy requirements placed in a calorie deficit that equated to about a 50% drop in total caloric needs on a daily basis.
For perspective, that’s about double the most extreme calorie deficit that someone will diet at in a general weight loss plan. So, what happened to the participants? Well, I think the picture tells the whole story:
These guys hardly look like people whose bodies are holding onto fat or gaining weight thanks to some evolutionary trick to keep them alive, right? That’s because that’s not how starvation works. At the end of the day, if we’re eating far fewer calories than we need on a daily basis, weight loss will eventually happen. And if the deficit is great enough, not only will that weight loss happen in the form of fat loss, but it will happen in the form of losing lean body mass, like muscle tissue, as well. More to that point: If starvation mode were an actual thing, we wouldn’t lose roughly 9 million people every year due to hunger, according to the Food and Agricultural Organization of the United Nations.
If starvation mode isn’t what’s slowing or stalling weight loss, then what is?
Good question! Remember how we said that this is a difficult question to answer because there is some nuance to what’s going on? Starvation mode might not be a thing, but metabolic adaptation most certainly is. In short, this is your metabolism’s response to changes in your body’s energy intake and expenditure. Basal metabolic rate (BMR) drives most of our overall caloric needs. Sustained periods of energy-restriction can decrease our basal metabolic rate, which occurs through multiple facets. When we lose weight, we carry less tissue around, which means less total resistance – thus we expend fewer calories. Ideally, this comes from reductions in adipose/fat tissue and not lean body mass or muscle tissue – fat tissue is not as metabolically active as muscle tissue, but still contributes to overall energy needs regardless of movement. Additionally, it is possible for the body to down-regulate metabolic needs for certain biological processes. This can include hormonal production, which requires calorie input – after prolonged periods of energy restriction, the body may begin decreasing processes that are not essential to sustain life (yours, that is) – such as sex-hormone production. It is, however, difficult to quantify these metabolic changes based on the current body of research and can certainly vary amongst individuals based on a host of reasons.
The more significant factor with this decrease in metabolic output has likely more to do with resting metabolic rate (RMR), which unlike our BMR, factors in daily activity levels. Fatigue builds the longer we sustain an energy deficit – for everyone, no exceptions. And one of the biggest contributors is a decrease in non-exercise activity that happens across this continuum, often subconsciously. We fidget less, we are less animated in our daily interactions, less inclined to get up and move more; we may park closer to go into work, the grocery store, etc.; perhaps more likely to take the elevator over the stairs – all things that may be harder to identify, yet contribute to decreasing our daily energy expenditure. But even during formal exercise, studies demonstrate that this fatigue contributes to burning fewer calories measured during a bout of physical activity – thought primarily to be contributed by diminished force potentiation (low energy availability means muscles struggle to produce similar contractile force as when we are adequately fueled). This is increasingly important to consider due to the impact exercise has on muscle retention rates.
Where the theory of starvation mode first came about.
Anyone who has ever attempted serious weight loss can attest to the fact that it’s not always easy. It tests our patience, our discipline, and our willpower, and it can also be a mentally exhausting thing. Especially when we hit a plateau and weight loss stalls.
You know that moment I’m talking about. When we’ve been dieting for weeks and seeing steady weight loss, then all of the sudden things start to slow down or stop completely. All the while, we’re doing everything we can.
- Hitting our numbers macronutrient targets as consistently as we can
- Prepping our meals and we’re sticking to the plan
- Lifting weights
- Monitoring/assessing non-exercise activity or total daily movement
Yet still, the scale refuses to budge.
At that point, it’s easy for us to chalk it up to some unknown evolutionary force that is hellbent on keeping us alive. After all, that’s a much easier explanation than coming to grips with the fact that we might just have to eat even less food than we are right now if we want to keep on losing weight.
Why having a coach can become valuable
When you’ve hit the point that weight loss slows down or stalls, having a coach to bounce your thoughts and ideas can be incredibly helpful. Deciding to keep on dieting isn’t a minor decision that should be taken lightly, especially if you’ve already been dieting for months on end. Dieting is a stressful process for the body. It asks a lot of us from both a mental and a physical standpoint, and the further we go, the more difficult it tends to be for us.
A coach can be a sounding board that helps you troubleshoot what might be going on. For example, maybe the reason our weight loss has slowed down is due to the fact that we’re actually eating more food than we even know, which happens to all of us, including Registered Dietitians. A coach can provide personalized guidance to help you determine how to approach our next steps by:
- Getting to know you on an intimate level and understanding your challenges
- Working with you 1:1 to implement a tailored plan
- Monitoring your progress and updating recommendations, as needed
- Providing ongoing support
A coach can help you determine that a diet break might be helpful right now. Or they can help you determine if you’ve been living so long in diet mode, playing into that metabolic adaptation, that taking some time to live in lifestyle mode might benefit your mental and metabolic health.
All of this isn’t to say that you need a coach to tell you that you’re not actually in starvation mode. After all, I hope that if you’ve made it this far, you understand that starvation mode doesn’t exist. But it is to say that weight loss and nutrition are highly nuanced and complicated topics, as we often talk about, and are topics that are rife with misinformation and half-truths. If we’re not careful, falling victim to those half-truths and pieces of misinformation can not only delay and hinder our weight loss efforts but they can also cause us to spend far more time than necessary trying to accomplish our ultimate goal.
