Metabolism is one of the most misunderstood aspects of health. People often blame their metabolism when they feel tired, struggle with weight, or notice stubborn belly fat — and they're not wrong. A sluggish metabolism can absolutely make it harder to feel and function well.
But here’s the catch: many people accidentally cause their metabolism to slow down by following habits they think are helping them get healthy.
What Is Metabolism, and Why Does It Matter?
Your metabolism is the sum of all the chemical processes your body uses to turn food into energy. It powers everything from digestion and hormone production to brain function and cell repair.
A faster metabolism helps your body burn energy more efficiently. A slower metabolism can lead to fatigue, difficulty losing weight, irregular digestion, poor mood, and more.
While genetics do play a role, your daily habits have a huge influence on your metabolic rate. That means the choices you make — with food, movement, sleep, and stress — matter.
Here are some things that might be slowing down your metabolism.
1. Not Eating Enough
One of the fastest ways to slow down your metabolism is to chronically under-eat. When your body senses a long-term energy shortage, it responds by conserving energy — which means burning fewer calories at rest.
To be clear, this is different from a calorie deficit, which is a moderate, intentional reduction in calories (paired with enough protein, strength training, and sleep) to support fat loss while preserving muscle. A basic calorie deficit, when done correctly, is sustainable for your body and generally healthy.
Chronic under-eating, on the other hand, often involves eating well below your energy needs for too long — without enough nutrients to sustain your metabolism. Over time, this can lead to muscle loss, hormonal imbalances, and slower calorie burn, making it harder to lose fat and easier to regain weight later.
Skipping meals, avoiding carbs entirely, or staying in a very low calorie range for too long can:
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Lower thyroid hormone output
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Decrease leptin (your “satiety” hormone)
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Reduce muscle mass
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Trigger more hunger & cravings later
In summary, a healthy deficit tells your body to use up stored fat while being safe and nourished.
Under-eating tells your body it’s starving and that it needs to conserve energy, store fat, and slow everything down.
2. Eating Too Little Protein
Protein is critical for maintaining lean muscle — and muscle is one of the biggest drivers of your resting metabolic rate.
The more muscle you have, the more calories you burn even when you're not moving.
The current recommended dietary allowance for protein is 0.8 grams per kilogram of body weight. However, most adults need significantly more protein than that to support muscle maintenance and metabolic health — especially during fat loss (1). The ViCera Diet recommends 1.0-1.4 grams per pound of desired body weight.
Low-protein diets can lead to:
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Slower recovery from workouts
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Increased appetite and snacking
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Reduced thermogenesis (the energy burned during digestion)
3. Sitting Too Much (and Moving Too Little)
Modern life makes it easy to be sedentary — but sitting for long periods tells your body that it doesn’t need much energy.
Even if you exercise a few times a week, being inactive for the rest of the day can lower your non-exercise activity thermogenesis (NEAT) — which plays a major role in daily energy expenditure (2).
Low NEAT levels have been linked to metabolic dysfunction, insulin resistance, and weight gain — even in people who exercise regularly (3).
Incorporating more movement throughout the day doesn’t have to be intense. Small things like walking after meals, standing more often, or doing light housework can help keep your metabolism more active.
4. Poor Sleep
Sleep is when your body recovers, repairs, and regulates hormones that directly impact your metabolism.
Just one night of poor sleep can reduce insulin sensitivity and increase ghrelin (the hunger hormone) (4, 5).
In addition to slower metabolism, chronic sleep deprivation is linked to increased fat storage, reduced muscle synthesis, and higher cortisol levels (which we’ll cover next).
Aiming for 7–9 hours of high-quality sleep per night is one of the most underrated ways to support your metabolic health†.
5. Chronic Stress
When you're constantly stressed, your body produces more cortisol — a hormone that, in excess, slows thyroid function, increases belly fat storage, and suppresses muscle building.
Over time, elevated cortisol can cause insulin resistance, poor sleep, cravings for high-sugar/high-fat foods, and a slower metabolic rate overall.
6. Frequent Crash Dieting and Cleanses
Repeated cycles of intense dieting or “cleansing” can cause long-term harm to your metabolism. When your weight drops too quickly — especially without enough protein or strength training — you tend to lose muscle, not just fat.
Each time you regain weight without rebuilding muscle, your metabolic rate dips lower than before. This is one of the key mechanisms behind yo-yo dieting and why it becomes harder to lose weight over time.
7. Ignoring Gut Health and Micronutrients
Your gut is responsible for absorbing the nutrients your metabolism needs to function.
A diet high in ultra-processed foods and low in fiber, fermented foods, or variety can compromise your gut flora and digestion, leading to nutrient deficiencies.
Eating a diet rich in real, whole foods can support gut health — and therefore metabolic health†.
What to Do Instead
If you’ve recognized some of your own habits above, the good news is, your body’s not broken — it’s simply adapted to the signals you’ve been sending it. And you can change that.
Here are the fundamentals to support your metabolism naturally:
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Eat enough, especially protein (at least 1.0-1.4g per pound of desired body weight daily)
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Build and maintain muscle through resistance training
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Sleep 7–9 hours a night
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Move often, even outside the gym
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Support your gut with diverse whole foods and fermented options like yogurt†
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Make time for activities that reduce stress
Like we’ve talked about before, increasing your muscle mass with some basic strength training and plenty of protein is the most effective way to boost your metabolism naturally.
Thankfully, there’s a variety of ways to get more protein in throughout the day. One simple and delicious way is by making a sweet drink (like a fruit smoothie or creamy milkshake) with some protein powder to enjoy after your workout.
There are plenty of protein powders out there, but ViCera’s is on the cutting edge of the market by using A2 protein from certified Regenerative Organic®, grass-fed beef organs and no artificial sweeteners, ever.
† We are required to say these statements have not been evaluated by the FDA. Products are not intended to diagnose, treat, or cure any disease.
Relevant Studies
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Weijs, P., & Wolfe, R. (2016). Exploration of the protein requirement during weight loss in obese older adults.. Clinical nutrition, 35 2, 394-398 . https://doi.org/10.1016/j.clnu.2015.02.016.
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Villablanca, P., Alegria, J., Mookadam, F., Holmes, D., Wright, R., & Levine, J. (2015). Nonexercise activity thermogenesis in obesity management.. Mayo Clinic proceedings, 90 4, 509-19 . https://doi.org/10.1016/j.mayocp.2015.02.001.
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Buscemi, C., Randazzo, C., Barile, A., Bo, S., Ponzo, V., Caldarella, R., Malavazos, A., Caruso, R., Colombrita, P., Lombardo, M., & Buscemi, S. (2024). Factors associated with body weight gain and insulin-resistance: a longitudinal study. Nutrition & Diabetes, 14. https://doi.org/10.1038/s41387-024-00283-5.
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Donga, E., Van Dijk, M., Van Dijk, J., Biermasz, N., Lammers, G., Van Kralingen, K., Corssmit, E., & Romijn, J. (2010). A single night of partial sleep deprivation induces insulin resistance in multiple metabolic pathways in healthy subjects.. The Journal of clinical endocrinology and metabolism, 95 6, 2963-8 . https://doi.org/10.1210/jc.2009-2430.
- Schmid, S., Hallschmid, M., Jauch-Chara, K., Born, J., & Schultes, B. (2008). A single night of sleep deprivation increases ghrelin levels and feelings of hunger in normal‐weight healthy men. Journal of Sleep Research, 17. https://doi.org/10.1111/j.1365-2869.2008.00662.x.
