Carb Refeed Calculator & Guide

What Is a Carb Refeed?

In short, a carb refeed is a short-term, strategic increase in carbohydrate intake designed to: 

• Replenish muscle glycogen
• Support key hormones involved in appetite, energy and metabolism
• Give a mental and physical bread from long dieting phases

If someone has been dieting for a long time and notices exhaustion, low mood, poor training and constant hunger, that can be a sign glycogen is low and a structured refeed may help.

Refeeds are also used by endurance athletes to help maximise energy stores in the lead-up to an event.

What is Glycogen?

Think of glycogen as a reserve energy pack stored in the muscles and liver - ready to fuel moderate to high intensity movement.

Here's how it works: 

1. We eat carbs.
2. They break down into glucose and enter the bloodstream for immediate energy.
3. Whatever isn't needed straight away is converted into glycogen and stores in the muscles (mainly) and liver (a bit). How much someone can store depends on muscle mass and training status (hence the calculator below, based on personal stats).
4. When we next come to exercise, the body first uses circulating glucose (anything we've just eaten), then taps into the glycogen to keep us going.
5. When we eat carbs again after training, we top those glycogen stores back up. This is why eating a carb-heavy post-workout meal is ideal for glycogen replenishment.

Glycogen is constantly going up and down - emptying with hard training, refilling when we eat.

Why Might Someone Need a Carb Refeed?

Here's the problem. When someone is in a calorie deficit, they're almost never fully refilling their glycogen stores. Overtime, this can lead to:

• Low energy
• Poor training performance
  
• A big spike in hunger

Part of that hunger response is related to hormones like leptin (the "I'm full" hormone) dropping, whilst ghrelin (the hunger hormone) rises - making us crave everything in sight.

This is where many people end up having an unplanned binge - usually on foods high in both fat and carbs (pizza, chocolate, crisps etc). 

The body can only convert carbohydrates into glycogen - not fat. So whilst the carbs do refill glycogen, eating these sorts of foods can also drive up calories and fat gain - undoing what could be weeks of hard work.

A structured carb refeed aims to avoid this. It allows us to eat thousands of calories over maintenance without gaining fat, provided the calories are made up from almost entirely carbs.

That’s why a clean, structured refeed beats a fat-heavy binge every single time.

We still need to think about calories overall, but done correctly, a refeed can refill those glycogen stores and keep us satisfied, steering us away from an unplanned binge and unwanted fat gain.

When Should You Refeed?

This is where a lot of people - even some coaches - go wrong.

If someone feels they "need" a refeed every week or two, it can be a sign that:

• Their calorie deficit is too aggressive
• Their carbs are too low
• Their training output is too high for their calorie intake

In these cases, it makes more sense to raise their overall weekly calories slightly so they can perform better, recover faster and avoid the mid-week crash.

A refeed should be done sparingly, different people will need different frequencies depending on their deficit and training load. Those with very low carb intake will likely deplete faster and need refeeds sooner. Those eating moderately can likely go longer.

Example:

If someone is taking GLP-1 medications and does only steps, they may last a few months until their glycogen finally depletes.

Compare that to someone who goes to the gym more often, they may deplete every month or so.

If someone feels that they need to refeed any sooner than every 2 (ish) weeks, it's a sign that their calories or carbs could be too low. 

In a nutshell, there isn't a one-size-fits-all schedule. Instead, it's better to learn the signs.

Common Signs You May Benefit From a Carb Refeed

1. Intense, persistent hunger

Not “I could snack” hunger - we’re talking more constant, “Oh lordy lord order the Domino’s and raid the cupboards” hunger. When food starts occupying every thought, the body is crying out for glycogen.

2. Low energy & poor training performance

Workouts that used to feel manageable now feel like wading through mud. Performance drops, motivation dips and everything feels harder than it should.

Some people may talk about how they can train whilst fasting. Their glycogen is already topped up, that's why they can. As soon as they hit a real deficit they'll likely fall into the same hurdle.

3. Flat, "Deflated" looking muscles

Each gram of glycogen can hold around 3-4g of water. Most people can store anywhere from 500-1200g of glycogen, depending on size and muscle mass. So imagine losing 2.5l of water from our muscles. That's why we look "flat" in the mirror.

More advanced, leaner lifters tend to notice this effect more clearly. 

4. You're still seeing the scales drop

If someone is in a confirmed calorie deficit and weight is trending down overtime, glycogen is being used.

If weight hasn't moved in a while, it's likely that they're not in a calorie deficit, and therefore not depleting glycogen.

How to Structure a Carb Refeed

💧 1. Hydration

A refeed can increase water storage by 1.5-2.5 litres. That's normal. Make sure water intake is higher than usual to support this, or you could feel drained and thirsty.

🥣 2. Plan ahead

The last thing we want is a chaotic, unstructured refeed.

If someone's aiming for a refeed between 3000-7000 kcal (yes, that's normal!), grams of fat can creep in fast. Make it easier by: 

• Pre-plan meals
• Log them in the Team RH App
• Get the right foods in the house in advance

Keeping fat intake low is key.

🍭 3. Start with Higher-GI carbs

Begin with faster-digesting, higher-GI carbs, such as: 

• Certain cereals
• White rice
• Fruit juice
• Honey, jam
• Crumpets or white bread products

These replenish glycogen stores quickly, and often help you feel more human again.

After that, move onto complex carbs, like:

• Oats
• Less surgary cereals
• Pasta
• Potatoes
• Rice

All of these help sustain glycogen refill across the rest of the day.

🧈 4. Keep fat low

High-fat foods slow digestion and add a lot of calories quickly. Ideally minimise:

• Nuts
• Cheese
• Fried food
• Creamy sauces
• High-fat cereals

Example:

✅ Crumpet with jam = perfect, low fat, low carbs

❌ Jordans Country Crisp = 11g fat per 100g — that adds up fast.

FAQ's

How many days should a refeed last?

One day. This means eating above your normal intake for that day, which will effect your weekly calorie average and if you're using the Team RH App, will effect your weekly average numbers.

Will a refeed "break" a weight loss plateau?

This can be a common misconception. 

A refeed doesn't magically speed up fat loss. Fat loss still comes down to calories in vs calories out. If progress has stalled, it's likely due to overall intake, tracking accuracy or changes in activity levels than simply "needing more food".

"I’m hungry - does this mean I need a refeed?"

Not automatically. Dieting will never feel like a spa break. We often see members inside Team RH having unnecessary refeeds, which should be avoided.

Only when extreme fatigue, very low energy and relentless hunger all line up, and weight loss has been dropping, it may be a sign to consider one. 

"I only walk do I need a refeed?"

The less intense the activity, the slower glycogen is depleted. Over a long enough dieting phase, even lower-intensity movers may benefit from a refeed, but frequency is generally lower. It's more about overall deficit and symptoms than the exact type of exercise.

"I’m scared to eat that many calories"

This is common, especially for people who previously struggled with overeating. Remember:

• During a refeed, the goal is to refill glycogen, not to abandon the plan.
• Extra carbs mainly go towards topping up that "energy tank" when it's depleted.
• The focus is still structure, not "cheat meal" thinking.

"I’m diabetic, can I do this?"

If you have Type 1 or Type 2, or any medical condition affecting blood sugar or insulin, you should speak to your GP, diabetes nurse or specialist before attempting a carb refeed. 

"I’m on GLP-1 Medication. Can I refeed?"

For those on GLP-1's, appetite, digestion and capacity are already heavily effected by the medication. Any large change in carb intake should be discussed with a prescribing clinician. We always advise this to members of our GLP1 plan too!

"Should I drop calories before or after a refeed to even it out"?

A refeed is, by design, a day of higher intake. Trying to "cancel it out" by removing calories either side usually defeats the purpose and can make adherence worse. 

"Will I gain weight?"

Yes - scale weight will almost certainly jump in the days after a refeed due to: 

• Higher food volume
• Increased glycogen
• Extra water and sodium

This is not the same as a sudden jump in body fat. As digestion and water balance settle, weight will drop back down and your true trend will show.

"Should I refeed before an endurance event?"

For endurance events, this is usually called carb loading. The principle is similar, but the goal is to fully maximise glycogen stores. This calculator is designed to half refill your glycogen stores whilst in a calorie deficit.

Notes for endurance athletes: 

• Endurance athletes usually practise a refeed beforehand (weeks before).
• Sudden fibre or sugar increases can cause digestive issues (stick to foods you're familiar with and practise hydration).
• If consuming all carbs in one day is a challenge, spread it over 48hrs. Remember, it takes 18-24hrs to fully refill glycogen. The last thing we want is to be on an endurance event with a less-than-ideal bowel issue.
• A lot of endurance athletes decide to refeed after an event as well, to restore glycogen stores after the event.

Want to learn about how to carb load for an endurance event too? Check out our separate article & calculator here!

Key Takeaway

A well-planned carb re-feed can:

• Replenish glycogen
• Restore hormones related to hunger and energy
• Improve training performance
• Boost mood and adherence

It's not a cheat meal, not an excuse for a blow-lout and not a magic plateau-breaker. Done properly - low fat, high carb, structured - it can be one of the most powerful tools in a dieting toolbox.