Intermittent Fasting for Beginners: What It Is, How It Works, and Whether You Should Do It

Related: Check out our guide on Fast Food Diet Guide.

Intermittent fasting has been everywhere for the last five years. Social media coaches swear by it. Some doctors say it's the future of metabolic health. Others call it a gimmick.

So what's the truth?

Here's the honest version: intermittent fasting is a useful tool for some people in some situations. It's not magic. It's not essential. But it's also not a scam. This guide will help you figure out whether it makes sense for you — and how to actually do it if you decide to try it.

Related: Check out our guide on Eat Out & Stay on Diet.

What Is Intermittent Fasting?

Intermittent fasting (IF) is an eating pattern where you cycle between periods of eating and not eating. It's not a specific diet — it doesn't tell you what to eat, only when to eat.

The most popular approach is 16:8 — you fast for 16 hours and eat within an 8-hour window. For most people, this means skipping breakfast and eating between 12pm and 8pm.

Other common protocols:

• 18:6 — Fast 18 hours, eat within 6 hours (noon to 6pm)
• 5:2 — Eat normally 5 days a week, restrict to 500–600 calories on 2 non-consecutive days
• OMAD (One Meal a Day) — Exactly what it sounds like. Hard to sustain, usually unnecessary.

For most beginners, 16:8 is the starting point. The rest can come later if you want to experiment.

How Does It Work for Fat Loss?

Intermittent fasting works for fat loss through one primary mechanism: it makes it easier for most people to eat fewer calories.

When you cut out breakfast and push your first meal to midday, you're often eliminating 400–600 calories from your day without feeling particularly restricted. You still eat the same foods in your two meals — you're just fitting them into a shorter window.

There's also a hormonal angle. During a fasted state, insulin levels drop. Lower insulin = your body can access stored fat more easily. This is real, but it's secondary to the calorie deficit. If you eat the same number of calories in 8 hours as you would in 14, the fat loss benefit largely disappears.

The key insight: intermittent fasting is a tool for managing calories, not a magic metabolic switch. For the complete explanation of calorie deficits, read how calorie deficits work for fat loss.

What Intermittent Fasting Doesn't Do

Let's clear up some myths:

It doesn't "reset" your metabolism. Your metabolism doesn't reset. There is no detox happening. Skipping breakfast doesn't cause your body to dramatically shift into fat-burning mode.

It's not better than three meals a day for fat loss. Multiple studies comparing IF to continuous calorie restriction with the same total calories show similar fat loss results. The advantage of IF is compliance — some people find it easier to skip breakfast than count calories at every meal.

It doesn't mean you can eat whatever you want. If your 8-hour window includes a pizza, a bag of crisps, two bowls of rice, and a large Nando's — you're not in a deficit. The eating window doesn't override calories in vs calories out.

Who Intermittent Fasting Works Best For

IF tends to suit people who:

• Skip breakfast naturally anyway — if you're never hungry in the morning, formalising this as a 16:8 protocol is basically zero effort
• Eat out frequently and prefer bigger meals — two satisfying meals feels more manageable than three smaller ones for some people
• Struggle with snacking — having defined eating windows eliminates the mindless grazing that ruins many diets
• Want a simple structure — "don't eat before noon" is easier to follow than calculating precise calories for every meal

Who Intermittent Fasting Doesn't Suit

IF is probably not the right tool if:

• You train early in the morning — fasted sessions can work, but if your sessions are intense and you're trying to build muscle, training with no fuel compromises performance. (For timing questions, read morning vs evening workouts to find what works best for you.)
• You get seriously hungry or irritable when you skip meals — suffering through fasting creates a miserable relationship with food and rarely ends well
• You have a history of disordered eating — structured restriction can be a trigger. Calorie counting with regular meals is a safer approach
• You're trying to gain muscle as a priority — protein timing and meal frequency matter more when building. Cramming all your protein into 8 hours is harder and can limit muscle protein synthesis. (Check out high-protein meal plans for muscle building for a better approach.)
• You're a parent or have a family schedule — if you eat with your family or need to feed kids in the morning, fasting often conflicts with real life

How to Start: The 16:8 Protocol

If you want to try IF, here's how to ease in without feeling terrible:

Week 1: Skip breakfast. Push your first meal from whatever time you currently eat it to one hour later. So if you normally eat at 8am, eat at 9am instead. Drink black coffee, green tea, or water in the meantime.

Week 2: Push the first meal to 10am. Most people barely notice the hunger by now.

Week 3: First meal at 11am. You're almost there.

Week 4: First meal at noon. Eating window is noon to 8pm. You're doing 16:8.

This gradual approach is far more sustainable than going cold turkey into a noon start on day one.

What you can have during the fast:

• Water (as much as you want)
• Black coffee or espresso (no milk, no sugar — both spike insulin)
• Plain green or black tea
• Sparkling water

What breaks the fast:

• Milk, cream, or sugar in coffee
• Fruit juice
• Any food

Intermittent Fasting and Muslim Fasting

If you already fast for Ramadan, you understand the psychological and physical side of fasting better than most. The principles are similar — your body adapts, hunger becomes manageable, and the focus on food decreases over time.

One thing to be aware of: during Ramadan, the eating window typically aligns with Iftar and Suhoor, which can make hitting your protein and calorie goals more challenging. See Gym During Ramadan for how to handle training and nutrition during this period.

Outside of Ramadan, standard IF protocols are fully compatible with halal eating and Islamic values — there's nothing in the practice that conflicts with the deen.

Protein Is Non-Negotiable

Whether you're doing IF or not, hitting your protein target is the most important nutritional variable for body composition.

The challenge with IF: you're fitting the same protein requirement into fewer meals. Calculate your protein needs first. If you need 160g of protein per day (roughly 2g per kg for an 80kg person), you need to spread that across 2–3 meals instead of 3–4.

That means your meals need to be more protein-dense. Prioritise lean meats, eggs, Greek yoghurt, cottage cheese, and protein shakes where needed.

For help tracking your protein and other macros, see How to Count Macros Simply.

What to Eat During Your Eating Window

This is where people go wrong. They fast perfectly, then eat whatever they want in the eating window and wonder why they're not losing fat.

A good IF eating window looks like this:

Meal 1 (noon or whenever you break the fast): High in protein, moderate carbs, some fat. Think: grilled chicken with rice and salad. Or eggs with wholegrain toast and avocado. Or a high-protein smoothie with oats.

Meal 2 (late afternoon/early evening): Your main meal. Prioritise protein again — fish, meat, legumes. Include vegetables for fibre and micronutrients.

Optional Meal 3 (before 8pm): A lighter meal or protein-rich snack. Greek yoghurt, cottage cheese, a protein shake, or a small meal.

The pattern: protein at every meal, vegetables where possible, carbs calibrated to your goals.

Should You Add Intermittent Fasting to Your Fitness Plan?

Related: Check out our guide on Eid Fitness Tips.

The short answer: only if it makes your diet easier to follow.

If you're currently eating three meals a day, tracking your calories, hitting your protein, and making progress — don't change anything. The best diet is the one you stick to.

If you're struggling with compliance, constantly grazing, eating too many calories without realising it, or looking for a simpler structure — 16:8 is worth trying for 4–6 weeks. If you want an even simpler starting point, the 24-hour fat loss kickstart is a one-day protocol to reset your habits. See how you feel. If it works for you, keep it. If it makes you miserable, drop it.

What matters far more than when you eat: what you eat, how much protein you're hitting, whether you're in a calorie deficit, and whether you're training consistently. Nail those, and you'll get results — with or without intermittent fasting.

• See also: Cardio vs Weights: Which Works?
• See also: Gym Motivation for Beginners
• See also: Overcome Gym Anxiety

FAQ

Will intermittent fasting slow my metabolism? Short-term fasting does not slow your metabolism — the research is clear on this. In fact, fasting for up to 72 hours can slightly increase metabolic rate. The concern about metabolism applies to prolonged, severe calorie restriction — not a daily 16-hour fast.

Can I build muscle while doing intermittent fasting? Yes, but it's harder. You need to hit your protein targets in a shorter window and ideally train within your eating window for optimal performance. It's possible — it's just not the most optimal setup for pure muscle building.

What if I get really hungry during the fast? Have black coffee or green tea — both suppress appetite. Stay busy. Hunger usually peaks and then subsides. If it's genuinely unbearable, your eating window might be too restrictive for your current body weight and activity level.

Can I do intermittent fasting and still go to the gym? Yes. Most people train in the late morning (just before breaking their fast) or in the afternoon/evening within their eating window. Both work. Fasted training is fine for moderate intensity sessions — for heavy lifting, having some food beforehand tends to improve performance.

Does it matter which 8 hours I eat in? For fat loss purposes, the specific window matters less than consistency. Most people find noon to 8pm works with their social life. Some prefer 10am to 6pm. Pick a window you can stick to seven days a week.

Do I need to fast every single day? No. Even 5 days a week of consistent 16:8, with a looser weekend approach, can produce meaningful results. Perfectionism is the enemy of consistency.

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If your fat loss has stalled and you're wondering whether IF could restart it, read the fat loss plateau guide first — the issue might be simpler than you think. Make sure you're hitting your daily protein target regardless of eating window, and don't underestimate how much sleep and recovery affect your results. For those interested in pairing IF with training to build muscle and lose fat simultaneously, the body recomposition guide explains exactly how to structure both.