Signs You’re Under-Fuelling Your Body
Signs You’re Under-Fuelling Your Body
People often talk about the effects of eating too much – but did you know that undereating is just as problematic? If you’re on a health & fitness journey, it can be easy to slip into under-fuelling your body. But this can lead to some significant impacts on your health.
So how do you know if you’re not eating enough to support your goals? There are several signs that are red flags to watch out for.
Why under-fuelling is not the goal
Your body is incredibly intelligent. It knows when to conserve energy to protect you and increase your chance of survival (unfortunately, it doesn’t know there is an abundance of high-calorie foods at McDonald’s 1km away!)
The body’s metabolism and appetite work together to keep you from losing too much body fat. But one of the ways they achieve this is by putting protective mechanisms into place when they aren’t getting enough calories in. And this leads to the development of symptoms – both in the short-term and the long-term.
Some of the long-term effects of undereating include:
Infertility
Impaired immune function
Increased risk of injury
Malnutrition conditions such as anaemia
Chronic fatigue
Osteoporosis and increased risk of broken bones
None of these are effects that you want to deal with – particularly if your goal is to be healthier!
So whether you’re working towards body recomposition and losing body fat, getting stronger in the gym or even other fitness goals such as running a marathon, eating enough is key.
Signs that you’re under-fuelling
Overeating in the evenings
This is one of the most common patterns I see, particularly in women. They skip breakfast or don’t eat until well into the day, and by the time evening rolls around, they tend to overeat. To compensate for their overeating, they go back to restricting themselves the next morning, and the pattern continues.
Overeating in the evening is a protective mechanism. It’s your body’s way of compensating for not getting adequate fuel during the day. So if you notice yourself overeating and unable to satiate your hunger at this time of day, it might be time to tweak up the intake earlier in the day.
Low energy
This symptom is pretty simple to understand. Calories are the body’s source of energy, particularly those that come from carbohydrates and fats. So if you’re not eating enough calories, your body can’t produce enough energy for your everyday tasks and routines.
You may feel a little less fatigued when you eat, as that’s when the body gets a hit of energy. But overall, it will feel like you have to drag yourself through the day.
Poor concentration & brain fog
The brain is dependent on sufficient fuel, and is often one of the first body parts to suffer the effects of undereating. As a result, you can experience:
Poor concentration
Impaired cognition
Brain fog
Memory loss
Dizzy spells
Feeling moody and irritated
Another aspect of an undernourished brain is the impact on your mood. Your mood is controlled by chemicals called neurotransmitters that are produced in the brain and gut. But when you don’t get adequate nutrition, your body struggles to produce enough of these chemicals to keep you balanced.
Mood swings, irritability, increased anxiety and depression are all potential signs of under-fuelling.
Changes to your menstrual cycle
There are many factors that can influence a menstrual cycle. But inadequate nutrition could be behind any changes you’ve noticed in your cycle.
This can include changes to menstrual flow (heavier/lighter), irregular cycles, anovulatory cycles (when you don’t ovulate) and complete loss of menstruation (amenorrhea).
Female hormones work in sync with other hormones including stress hormones, thyroid hormones and blood sugar-regulating hormones. When you don’t get enough food, the body errs on the side of caution and reduces your risk of falling pregnant by altering the balance of these hormones. This is also why long-term undereating leads to infertility.
Changes in bowel movements
Obviously there are countless causes of digestive changes. But if you haven’t changed your diet recently or consumed foods you’re intolerant to, constipation can be a common sign of under-fuelling.
Why? There is less food in the digestive tract, and it moves slower through your system. This can become a vicious cycle, as constipation can lead to loss of appetite.
Keep in mind that constipation isn’t just about hard-to-pass bowel movements. If you’re not going at least daily (ideally 2-3 times), that can also be constipation.
Feeling constantly cold
Are you shivering even on warmer days? While everyone has their own unique temperature setpoint, this can be a sign that you’re not eating enough.
The body requires a certain number of calories to maintain body temperature. Undereating can also lead to a reduction in thyroid function, which reduces your internal temperature and slows your metabolism right down.
Thinning hair & brittle nails
Just like any other part of the body, hair and nails rely on a variety of nutrients to stay healthy, happy and strong. These include macronutrients (protein and healthy fats) as well as micronutrients (B vitamins and vitamin E).
When you’re undereating, the body will prioritise energy and nutrients for the vital parts of the body. Your brain, heart and lungs will get the lion’s share of fuel. But your hair, skin and nails will end up missing out. As a result, you’ll see more physical symptoms such as thinning hair, hair loss, brittle nails and dull skin.
Plateaus in your progress
Noticed that your workouts are getting worse, rather than better? Have you stalled at the same weight for weeks at a time, no matter what you do? These can all be signs that your body isn’t getting enough nourishment to continue progressing.
We need enough nutrients and calories to put on muscle, to support metabolism, to stay out of fight-or-flight mode. The last thing you want to do if you have goals to change body composition or hit new PRs in the gym is to restrict your calories too far.
The good news?
If you do suspect you’ve been under-fuelling, many of these symptoms will be alleviated within a short time if you increase your food intake. So it’s easy for you to feel better and continue on your health journey – just add in some extra nourishment!
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Hey there, I’m Rachel!
NUTRITIONIST, PERSONAL TRAINER, WELLNESS COACH
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While we make every effort to make sure the information in this website is accurate and informative, the information does not take the place of medical advice.