August 4, 2025
5 reasons why undereating will wreck your gym goals
Making sure you eat enough could be the secret weapon to hitting new PBS.
It doesn’t matter what you’re chasing; whether it’s a deadlift PB, a set of toned abs or a speedy 5km run, one thing is for sure: food is fuel. But a lot of gym goers fall into the dangerous trap of eating too little. Perhaps in a bid to lose weight, avoid an uncomfortable tummy during workouts or simply because they’re trying to clean up their diet.
However, we’re here to tell you that falling into the undereating trap, won’t do your gym goals any favours. In fact, it could actually wreck your chances of hitting your goals. That’s because your entire body needs food to function. You wouldn’t drive a car without fuel, so why think you can train without food?
It’s not just undereating in general that can cause problems; undereating the right type of foods can also cause problems. If you’re struggling to hit your goals at the gym, then a lack of food might be the problem.
It’s not just undereating in general that can cause problems; undereating the right type of foods can also cause problems. If you’re struggling to hit your goals at the gym, then a lack of food might be the problem.
1 - You’ll struggle to build muscle
Lifting weights is a big factor in your muscle-building journey. But muscles won’t repair, recover and grow without enough food and the right nutrients, in particular carbs and protein.You may have heard of the term ‘bulking phase’, where the aim is to maximise muscle growth and strength through a calorie surplus and intense resistance training. Calories are essential here to build muscle. For a ‘cut phase’, where the aim is to lose fat while maintaining muscle, a high protein diet is essential to avoid muscle loss.
If you’re in a severe calorie deficit, your body might even start to break down your muscle for energy, which is the total opposite of what you’re trying to achieve.
2 - You’ll lose motivation
A lack of food can leave you tired and fatigued. If you’ve ever hit the gym when you’re low in energy, you’ll know what a struggle it can be! Motivation plummets and you simply don’t have the drive to work hard.3 - Your hormones might take a hit
Food and calories do more than just fuel your workouts. They also support your hormones which affect a number of things from your metabolism through to your recovery and mood. For men who aren’t eating enough, levels of the hormone testosterone can take a hit; this can have an impact on muscle growth, strength and even mood. For women, long term under-eating can lead to missed periods as well as issues with mood.
4 - You’ll plateau
If you’re hoping to lose weight, then a calorie deficit is the way to go. But drop your calories too low and your metabolism will likely slow down as your body tries to conserve energy by burning fewer calories throughout the day. With a slow metabolism, your fat loss might stall so you’re left feeling frustrated. Remember: every system in your body needs fuel.5 - Your recovery will slow down
When you train, your muscles break down. When you rest and feed your body, your muscles and body recover and come back stronger. But without enough food, your recovery can slow down and your risk of injury can increase. More injuries can mean you struggle to train efficiently, further wrecking your chances of hitting your gym goals.Don’t miss these
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