Something people don’t talk about enough is sustainability in fitness.
You might grasp the concept, but do you really know what it feels like?
At the beginning of a marathon, everyone looks like they’re going slow. While it would probably feel good to sprint in front of everyone and look like you’re in first place for a while, it almost certainly wouldn’t last to the end of the race.
In fact, with most races, the person who’s leading at the beginning is very rarely the winner. Good athletes know that in order to win, they need to play the long game and choose a pace they can keep up, even if they have way more to give at the beginning.
It’s the same thing when it comes to dieting. Crash diets are like trying to win a marathon by sprinting 100ft bursts and then collapsing. They promise fast results but leave your metabolism, mood, and mindset in the dust.
Sure, you might lose weight fast in the beginning, but what happens next? You gain it back, you feel more tired, you get hungrier. You feel like a failure.
But you’re not the problem. The diet is.
What Is a Crash Diet?
Crash diets usually mean eating way too little — like 800 to 1,200 calories a day — or cutting out entire food groups to try to lose weight fast.
At first, the scale drops. But behind the scenes, your body is panicking.
When you don’t eat enough, your body goes into survival mode. This is called metabolic adaptation, and it’s not your friend (1).
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Your metabolism slows down to save energy.
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You lose muscle, which means you burn fewer calories — even at rest.
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Your stress hormone (cortisol) goes up.
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Your hunger hormone (ghrelin) spikes, which can make you think about food constantly.
Basically, your body thinks you're starving, and it does everything it can to stop the weight loss.
Crash diets make your body fight you instead of work with you.
Muscle Loss = Slower Burn
One of the worst parts about crash dieting is the loss of muscle.
Muscle isn’t just for athletes or bodybuilders. It’s a fat-burning engine. The more muscle you have, the more calories your body burns all day long, even when you're just sitting.
When you lose muscle, your metabolism hits the brakes and fat loss gets even harder.
The Yo-Yo Nightmare
Ever heard of yo-yo dieting?
That’s when you lose weight fast, gain it back, try another diet, repeat.
Each time this happens, your metabolism gets more confused, your muscles take more damage, and your body is thrown off. Along with posing significant health risks (including type 2 diabetes and cardiovascular problems), emotionally, it can feel exhausting (2). Physically, it can make fat loss feel impossible.
This constant back-and-forth trains your body to hold on to fat, not let it go.
There’s a Better Way
You don’t necessarily need to eat less. You need to eat better and train smarter.
🍲 Eat real food, and splurge smart
Focus on:
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Protein (chicken, eggs, fish, beef, Greek yogurt, cottage cheese)
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Healthy fats (avocado, butter, olive oil)
- Fiber (veggies, fruits, whole grains)
These foods keep you full, build muscle, and support your hormones.
When you do splurge, make sure you’re tracking how it fits in with the rest of your eating. Tracking is truly the best way to make sure your diet stays consistent. Guessing won’t work.
🤸 Move your body
Walk more. Lift weights. Don’t obsess over cardio.
Strength training is the best thing you can do for your metabolism. (read more here)
🍂 Ditch the scale obsession
Measure success by:
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Your energy
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Your strength
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Your consistency
And not just the number on the scale.
✅ Reverse diet if needed
If you've been under-eating for a long time, it may take some time to repair your metabolism. This is where reverse dieting comes in: you slowly add back calories and let your body heal.†
Let’s be real: crash diets are tempting. They promise fast results. But those results come at a cost. You feel worse. You burn fewer calories, you crave more junk, and you trust yourself less.
Bottom line is, it’s not worth it.
Instead, eat enough to fuel your body. Move in ways that build strength. Give your metabolism a reason to work for you, not against you.
Slow and steady doesn’t mean boring. It means smart. It means long-term wins instead of short-term letdowns.
It’s time to break up with crash diets and give your body the fuel it actually needs to thrive. If you want a guideline on how to start a diet that will be sustainable for you, check out our free ViCera Diet Guide. It’s a flexible plan that can be tailored to your unique needs and preferences, and a great place to start if you want to ditch crash dieting for good.
† These statements have not been evaluated by the Food and Drug Administration. This article is for informational purposes only and is not intended to diagnose, treat, cure, or prevent any disease.
Works Cited
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Ravussin, E., & Redman, L. (2020). Metabolic adaptation: is it really an illusion?. The American journal of clinical nutrition, 112 6, 1653-1654 . https://doi.org/10.1093/ajcn/nqaa308.
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Roybal, D. (2005). Is "Yo-Yo" Dieting or Weight Cycling Harmful to One's Health? - eScholarship. , 7.
