Skip to content


Find out more

Fitness Starts Here

Lose Weight Fast: How to Burn Fat Quickly and Healthily

how to lose weight fast

It’s definitely possible to – under the right circumstances – lose weight very rapidly, but is this the best way to go about things? The common consensus amongst many trainers and nutritionists is that ‘healthy’ weight loss should take place at a rate of around 0.5-1kg per week. However it must be said – this figure is somewhat plucked out of thin air and it’s entirely possible to lose weight much quicker than this and be completely safe and healthy while doing so. Rates of weight loss (or weight gain) will depend on a single, simple equation.

calories (energy) consumed – energy expended = weight loss/weight gain

The bigger the ‘negative’ number we come out with each day the faster we will lose weight.

When looking at this equation, the calories consumed portion is simply the energy from the food we eat. For maximal rates of weight loss, you basically want this number to be as small as possible, while still providing your body with all the essential nutrients and energy it needs to stay healthy.


This is very specific to each person. Smaller people need less calories than bigger people, so what might be a small amount of food/calories for one person might be a lot for another. There are however some nutritional ‘rules’ you should follow when losing weight to make sure you stay healthy and safe in the process.


This is essential as you want to make sure any weight you lose is from stored body fat and not muscle tissue. A high protein diet – consuming anywhere between 1.5-3g of protein per kg of lean body weight – especially when combined with exercise, will help you protect muscle tissue.

If you don’t have a clue about what your lean bodyweight is, don’t worry, a simple estimate will do. Ask a trainer to help you figure this out if you are stuck!


Like protein, fats are an essential nutrient that’s required by your body for optimal health, so you need to make sure you’re getting enough of it and the right types too. I would suggest you aim to consume at least 0.8g of fat per kg of lean bodyweight from mostly unsaturated sources such as olive oil, avocado, nuts and seeds.


Although carbohydrates have often been (and completely undeservedly) given a bad reputation, they are an important fuel for high intensity exercise and resistance training. Consuming some carbohydrates will definitely be of benefit and help support your energy expenditure by giving you more fuel to train and function in day to day life. The amount of carbs included in your diet will depend on many factors, but in my experience 1-2g per kg of bodyweight per day should keep most people functioning fairly well.


Try to eat mostly whole, unrefined and unprocessed foods (including shakes or juices!). These types of foods will help keep you fuller for longer and also ensure you have enough fibre and micronutrients in your diet to keep you healthy. Bulk out your diet with plenty of greens, choose whole grain and starchy carbohydrates for energy as they also have more food volume and will help control hunger.

As an example, an 80kg person with 20% body fat (equating to a lean mass of around 64kg), might aim for a protein intake of around 130g (64 × 2g/kg), fat intake of around 50g (64 × 0.8g/kg) and carbohydrate intake of around 100g (64 × 1.5g/kg). This comes to the grand total of approximately 1370 calories.

But just because you can lose weight faster by dropping to a low calorie intake, does it mean you should?

Some people may consider this to be a low intake for a person of that size, but we also need to take into consideration how much energy they expend in other ways, how long they are going to stay in a large calorie deficit for, how they feel and their mood on those few calories relative to how quickly they want to lose weight. However, if you struggle to get to the gym, have a sedentary job which requires working long hours, then you might have to go to lower calories to lose weight without exercise and the extra energy output it provides.

The bigger the calorie deficit, the hungrier a person is likely to be (although this is not always the case) and the more cravings they are possibly going to have. Just because you can lose weight rapidly does not mean it is the easiest or most sustainable way to do things! Interestingly though, some of the most recent research shows that rapid weight loss is not only safe in the short term, but actually yields better long term weight maintenance results than ‘slow and steady’ dieting.

Weight maintenance is largely going to be dependent on how well a person controls their eating habits after they have achieved their weight loss goal, returning to previous habits will likely lead to weight regain. This is the main problem with crash dieting – it does not teach the value of foods or promote any kind of back-out strategy to maintain the person’s new weight.


That’s calories consumed taken care of, but what about energy expended? This can be increased by hitting the gym and maximising your energy expenditure while you’re there. Using high intensity classes can really ramp up your energy expenditure in a short period of time, but any activity you enjoy will help support weight loss if it gets you to expend more energy and burn those calories.

In addition to hitting the gym, you can also burn a ton of energy by increasing your non-exercise activity. Things like walking to the gym, cycling to work, doing the gardening, walking to the shops or walking the school run instead of taking the car. People hugely underestimate how much of an impact this can have on weight loss and it is absolutely the first thing I suggest people look to increase if looking to lose weight.

Some people see rapid weight loss as ‘wrong’ but losing 10lbs fast, in the space of two weeks for example, might be completely acceptable in some people depending on their starting point, how active they are and of course their genetics. The important thing to note here is there are so many factors that influence rates of weight loss to not beat yourself up if things are going slower than you would like.

As long as you have found a combination of nutrition and exercise that is working for you consistently it will get you to the same place as those who lose weight more rapidly. But if you are looking to speed things up and can handle it then there’s nothing wrong with being a bit more active, hitting the gym more often and working on maximising your calorie deficit as long as you can still function properly in day to day life.

About Paul Rimmer
Throughout the course of his academic studies, Paul has covered many areas related to sport science, including nutritional biochemistry, physiology, psychology, elements of physiotherapy and nutrition and exercise programming. Paul has obtained a bachelor’s degree in Sports, Health, Exercise and Nutrition, a master’s degree in Sport Injury and Rehabilitation and his doctorate in Healthcare Science.

Since leaving academia Paul has created his own fitness content and education businesses providing evidence based health and fitness content for various companies and individuals within the fitness industry as well as delivering courses and seminars covering many aspects of health and fitness. He also coaches several physique athletes and weight loss clients, putting his academic knowledge into practice in a real world setting.

Paul is extremely passionate about the need to educate people on evidence based nutritional and training practices, working as a consultant to many trainers and coaches around the world to help them develop their knowledge and provide better service to their clients.



Related Posts

How To Dress For Your Goal Weight

How to make sure your running doesn't hinder your strength gain

5 Daily Goals To Lift You Up And Escape Depression