The Fastest Way to Lose Weight — and Keep It Off

Last updated on March 22, 2026 at 08:01 pm

Let’s be honest about something. When people search for “the fastest way to lose weight,” they’re not looking for a lecture about patience and portion sizes. They want to know what actually works — and they want to see results without losing their mind or their social life in the process.

I get it. I’ve been there.

Here’s what I’ve learned through years of studying nutrition science and putting it into practice in my own life: losing weight quickly is absolutely possible, and it doesn’t have to be extreme. But the approach matters enormously. Crash diets and calorie counting tend to fail because they fight against your body. The methods I’m going to share work with your body — and the results they produce tend to stick.

The two pillars I come back to, personally and in the 21-Day Challenge I created, are intermittent fasting and whole food eating. Used together, they are a genuinely powerful combination. Let me explain both properly.

Intermittent fasting: why it works and how to find your method

Intermittent fasting isn’t really a diet — it’s a pattern of eating. Rather than changing what you eat, it changes when you eat. And that shift alone can have a significant impact on weight loss, gut health, and how you feel in general.

I personally practise intermittent fasting around three times a week. For me it’s become a natural rhythm — part gut reset, part structure, part simply feeling lighter. Research confirms that many people find it easier to sustain than traditional calorie restriction, precisely because it doesn’t require you to weigh food or track every meal. [1]

There are three main methods. Here’s how each one works and who it tends to suit:

The 16:8 method — the easiest place to start

This is the most popular form of intermittent fasting, and the one I’d recommend if you’re new to it. You eat within an 8-hour window and fast for the remaining 16 hours — most of which happens while you sleep.

In practice, a simple version looks like this: finish dinner by 8pm, skip breakfast, and have your first meal at noon the next day. Coffee or tea in the morning is fine — just no milk or sugar during the fasting window.

When you sleep, your body burns through the energy from your last meal and then switches to burning stored fat. A 2016 study found that when combined with regular exercise, the 16:8 method can help reduce body fat while preserving or even building muscle. [2] By extending the overnight fast a few hours, you’re simply maximising the time your body spends burning fat rather than glucose.

The key: what you eat in your 8-hour window still matters. Intermittent fasting doesn’t cancel out a diet built on processed food and refined carbohydrates.

The 5:2 method — for those who prefer weekly structure

With the 5:2 approach, you eat normally for five days and significantly reduce your calorie intake on two non-consecutive days — around 500 calories for women and 600 for men on those days.

Some people find this easier than daily fasting because the restricted days feel finite and manageable — you know tomorrow is a normal day. Others find the very low calorie days hard to navigate socially or energy-wise. It’s genuinely personal.

One thing to watch: the five normal days need to stay normal. The 5:2 method fails when people unconsciously compensate by eating more on unrestricted days. The goal is not to make up for the deficit — it’s to let the deficit do its work.

The Eat-Stop-Eat method — a full reset

This is the most intensive approach: a complete 24-hour fast on one or two days per week, eating normally on the rest. You’re not restricting calories — you’re simply not eating at all for a defined period.

I think of a full-day fast as a reset button. It’s something I find genuinely useful after a weekend of indulging — a Monday fast can bring you back to baseline and set up the week well. It’s not for everyone, and it’s not something I’d recommend starting with, but for people who have built up a fasting practice, it can be a powerful tool.

During any fasting period, staying well hydrated is essential. Water, herbal teas, and black coffee are all fine.

The most important thing about intermittent fasting

Whichever method you choose, the research is clear that the success of intermittent fasting depends almost entirely on what you eat when you’re not fasting. [3] Think of it this way: fasting creates the space for fat burning — whole foods fill that space with the right fuel. The two work together.

Eat whole foods — this is the part that makes the difference

Intermittent fasting without changing the quality of what you eat will only get you so far. The real transformation comes when you combine fasting with a diet built around whole, minimally processed foods.

This doesn’t mean going vegan. It doesn’t mean never eating meat or dairy again. It means making real, whole ingredients the foundation of your meals — and pushing ultra-processed food to the edges.

Why whole plant foods support weight loss so effectively

Most plant foods are high in water content and fibre, which means they fill you up without a high calorie load. You can eat a genuinely satisfying volume of food while naturally consuming fewer calories — without counting a single one.

A 2019 study looking at plant-based diets and weight loss found that shifting towards plant foods can reduce body fat through several mechanisms — including improved satiety, better insulin sensitivity, and a positive effect on gut bacteria. [4] The gut connection is one I find particularly compelling, and it’s something we dig into deeply in the 21-Day Challenge.

You don’t need to overhaul everything overnight. Start by crowding out — adding more whole foods to your plate naturally leaves less room for the stuff that doesn’t serve you.

What a whole food day actually looks like

Practically speaking, a whole food approach means meals built around vegetables, legumes, whole grains, eggs, fish, good quality dairy (I love a homemade yoghurt or a good skyr), nuts, seeds, and fruit. It means cooking from scratch most of the time — which, yes, takes more effort, but also means you know exactly what’s in your food.

The payoff isn’t just weight loss. It’s energy, sleep, skin, digestion, and mood. Weight loss is often the first thing people notice — but it’s rarely the only thing that changes.

Cut the ultra-processed foods — this is where most weight hides

If there’s one change that makes the biggest difference for most people, it’s this one. Research estimates that approximately 60% of caloric intake in the average Western diet comes from ultra-processed food. [5] These are products engineered to be hyper-palatable — high in refined sugar, salt, and industrial fats — and they make it extremely difficult to feel full or regulate your appetite naturally.

The most impactful swaps are often simpler than people expect:

• Homemade or whole grain bread instead of packaged white bread
• Lentil soup or a grain bowl instead of a ready meal
• A handful of nuts and fruit instead of packaged snacks
• Water, herbal tea, or homemade kombucha instead of sugary drinks
• Plain full-fat yoghurt with fresh fruit instead of flavoured, sweetened yoghurt

None of these swaps require perfection. They just require a gradual shift in what you reach for by default.

Putting it all together: what a typical week looks like

Here’s what combining these approaches might look like in practice — this is close to how I personally structure my week:

• Monday: Full fast day or 16:8, coming off the weekend — a natural reset
• Tuesday–Friday: 16:8 fasting on 2–3 of these days, whole food meals throughout, cooking from scratch where possible
• Weekend: Flexible — real food still at the centre, but room for enjoyment and eating socially without guilt

This isn’t a rigid programme — it’s a rhythm. And rhythm, over time, is what produces lasting results.

Julie, one of the participants in the 21-Day Challenge, put it well: “I now own my choices in regards to what and when to eat. I especially like my Mondays when I do the water fast — it feels like the best way to start the week, a bit like a reset button after my little treats over the weekend.”

Joost lost 8.5kg in three weeks following this approach alongside gym sessions. Mathilde lost 4kg postpartum in 21 days with minimal exercise. Results vary — but the direction of travel is consistent when the method is followed.

The bottom line

The fastest way to lose weight isn’t a magic supplement, a 500-calorie crash diet, or cutting out entire food groups forever. It’s a combination of giving your body proper fasting windows and filling your eating windows with real, whole food.

These two things work with your biology rather than against it. They’re sustainable. And for most people, they produce noticeable results within the first two to three weeks — which is exactly why the 21-Day format works so well.

If you want a guided, structured programme that takes you through this day by day — with meal plans, 200+ recipes, trackers, and video modules — the Eat Healthier in 21 Days Challenge was built for exactly this. You can start any time and go at your own pace.

And if you’re an athlete looking to manage weight and performance at the same time, the Plant-Based Athlete course covers nutrition for performance and body composition specifically.

The information in this article is for educational purposes. If you have an underlying health condition or are taking medication, please consult your doctor before making significant changes to your diet or fasting routine.