Why You Need To Eat More... Not Less
We are born into a society where we are persistently told to eat less and do more. As a dietitian in practice for over 8 years and specializing in eating disorders and sports nutrition, I’ve seen how this information does a serious disservice not only to our physical health but also to our mental health.
Humans have been evolving for thousands of years, and to have made it this far, our bodies have adapted to a variety of situations. We have survived famines, plagues, pandemics, and periods of surplus. Every one of these scenarios has forced our bodies and physiology to adapt and change to survive. Our body has learned how to live on minimal energy (calories), through nutrient deficits and times of poor sanitation.
Just because we have survived, this does not mean that we have thrived.
What happens when you eat less?
Contrary to popular belief, we don’t only burn calories through exercise. If you are doing intentional exercise, this only equates to about +/- 10% of your overall energy expenditure (1). Our bodies burn energy AKA calories simply by existing. Yes, your heart, liver, lungs, and every single cell in your body require calories to function.
When we experience periods of low energy intake, whether this is intentional (dieting, forgetting to eat, or eating disorders) or situational (decreased food access), our bodies will automatically decrease our resting metabolic rate (RMR), which accounts for 60-75% of the total energy you burn in a day (1). Our body does this to keep us alive. Remember, it’s had thousands of years to adapt and has complex mechanisms in place to survive a period of low energy intake. These adaptations to our metabolism can be short-term or long-term (2).
This means that if you’re restricting calories, you may lose weight initially, but once you return to eating more (because long-term energy restriction and dieting are unsustainable), your body will regain the weight, and then some. This is because your RMR adapted to conserve… thus burning fewer calories at rest, resulting in weight gain.
Additionally, low-calorie diets or even “monitoring” your calorie intake increases physical and emotional stress levels. Stress has a significant impact on our hormones (increases cortisol and epinephrine, for example) which impacts how our bodies respond to food (3). Here are just a few things that happen when we are stressed:
Under stress, your body will decrease insulin (glucose/sugar storage hormone) production while also increasing the amount of sugar that can be naturally made in your body (gluconeogenesis). Because insulin is in charge of getting sugar out of our bloodstream, it is down-regulated, which depletes our cells of essential energy and nutrients. This will lead to an increase in hunger hormones and often results in feeling “out of control” around food (3).
Stress, specifically chronic stress will cause your body to increase the production and release of cortisol. Cortisol like insulin is a storage hormone and increases the storage of fat from our bloodstream (triglycerides) because fat is an energy-dense molecule, our body is doing this to conserve for future use or periods of low energy intake (4).
How dieting creates a scarcity mindset
When our bodies don’t have enough available food, psychologically this creates a scarcity mindset. We have all seen this first hand at the beginning of the COVID-19 pandemic with food and toilet paper hoarding. A scarcity mindset, in the simplest of terms, means that you are living your life in a place lacking as opposed to a place of abundance and security. It is the idea that if one person has more of something, you automatically have less. This mindset is seen in also seen in money, personal relationships, and even systemic racism.
Living in a scarcity causes your brain to hyper-focus on the object that is “lacking”, causing you in this case, to be obsessed with food. This might lead you to constantly think about food and when your next meal is, planning what it is going to be, and dreaming about foods you may not even truly like. It may even feel like you have tunnel vision and the only thing you can see is food (5). Once we finally have access to food or foods we have restricted, we will often eat more than we are comfortable with or full-on binge. This is a cycle… restrict—binge—restrict because we feel guilty— and subsequently binge again.
“Until we can feel safe again with food, this cycle will continue”
It may sound counterintuitive, but to get out of this mindset, we need to live in abundance. We need to eat more overall and permit ourselves to eat foods we have previously deemed as “bad” whenever we want, without guilt. This is scary at first… Really scary. But until we can feel safe again around food, this cycle will continue. For more on the scarcity mindset, listen to this great Hidden Brain podcast.
But won’t I perform better at a lower weight?
No. Lighter isn’t faster, or stronger, or more powerful. When you lose weight, it is impossible to lose only fat or adipose tissue. Weight loss always results in a loss in muscle mass, strength, bone density, water, and often minimal fat loss. It is estimated that 25% of weight loss is muscle mass. In lies the problem, muscle tissue is one of the main drivers of energy expenditure and how much you are burning calorically overall, so even if you’re losing weight, you’re also losing muscle mass, thus burning less energy throughout your day. It is much more difficult to gain muscle mass than lose it, meaning we need to do everything in our power to maintain, build, and preserve what we have.
Your muscle tone, appearance, and definition are primarily based on your genetics. This is why if we all moved and ate the same way, we still wouldn’t look the same. Some other factors include time under tension (years of training), how you nourish yourself around training (before, during, and after), as well as how much time you spend recovering. Never taking a rest day is not a flex, it is a sign of a disordered relationship to exercise and will eventually lead to burnout, fatigue, and injury.
Eating less and training more may be manageable for some time, but this creates an energy deficit, and as mentioned above is unsustainable. A deficit in nutrients and calories will always decrease your recovery and increase injury risk. Remember that your brain, heart, and other organs are more essential than repairing your quad muscles after a heavy leg day. If your body is forced to choose between repairing muscle tissue or maintaining basic function, you know which will be the winner.
If a deficit continues for prolonged periods you will eventually end up overtrained and in a state of low energy availability. This is a state where your body does not have enough energy to support physiological functions to maintain optimal health. In athletes, this is called Relative Energy Deficiency in Sport (RED-S). This causes gastrointestinal issues, impaired muscle strength, poor muscle recovery and power, hormonal changes, and bone abnormalities, and slowly degrades your mental and cognitive health (6). As you can see, it isn’t as simple as calories in, calories out. This is because we are humans, not machines.
So if it isn’t calories in, calories out…
Since food is not as simple as calories in and calories out, then what is it? Well, I will be the first one to tell you that your relationship with food is so much more important than the food you’re eating. Even if you are eating “super clean” and you’re micromanaging and overthinking food, that also causes physiological changes to your body (which we already learned about), and if this is taken to extremes is what we call orthorexia.
Eating enough will increase not only how much energy you’re taking in but will also increase the nutrients (vitamins, minerals, phytonutrients, and antioxidants) your body has access to. You don’t need fancy supplements to meet your nutrient needs (learn more about if you should supplement here). Connecting back in with your body to better understand why you eat is essential to healing your body for optimal performance, recovery, and your relationship to food.
Eating more can help to reverse the negative effects of low energy availability, abnormal hormones, and our metabolism. It can help to normalize our physiology and improve our mental health. So if you want to continue doing what you love, for life, here is my invitation to eat more.
If you need help eating more and eating enough to meet your needs and support your training, book an appointment with Abby Chan, MS RDN here!
Apfelbaum MJ, Bestsarron J, Lacatis D. Effect of caloric restriction and excessive caloric intake on energy expenditure. Am J Clin Nutr 1971; 24: 1405–1409.
Fothergill E, Guo J, Howard L, et al. Persistent metabolic adaptation 6 years after "The Biggest Loser" competition. Obesity (Silver Spring). 2016;24(8):1612-1619. doi:10.1002/oby.21538
Tomiyama AJ, Mann T, Vinas D, Hunger JM, Dejager J, Taylor SE. Low calorie dieting increases cortisol. Psychosom Med. 2010;72(4):357-364. doi:10.1097/PSY.0b013e3181d9523c
Epel ES, McEwen B, Seeman T, et al. Stress and body shape: Stress-induced cortisol secretion is consistently greater among women with central fat. Psychosom Med. 2000;62(5):623-632.
Mountjoy M, Sundgot-Borgen J, Burke L, et al. Br J Sports Med 2014;48:491–497
Folta SC, Anyanwu O, Pustz J, Oslund J, Penkert LP, Wilson N. Food Choice With Economic Scarcity and Time Abundance: A Qualitative Study. Health Educ Behav. 2021 Oct 12:10901981211045926. doi: 10.1177/10901981211045926. Epub ahead of print. PMID: 34636284.