How quickly can I lose weight?

You can lose weight extremely quickly if you don't eat for 4 days a week, exercise 10 hours a day (this is, of course, tongue in cheek and isn't recommended). But just because you can lose weight in this way, it doesn't mean you should.

My clients often ask me how quickly they can expect to lose weight.

This could be because they have a deadline in mind or want to lose weight for an upcoming event, like a holiday or wedding.

But, unfortunately, the answer isn’t as easy as giving them a specific weight loss timeframe.

Here’s why:

The simple answer to “How quickly can I lose weight?” is “very quickly”.

You can lose weight extremely quickly if you don’t eat for 4 days a week and exercise 10 hours a day (this is, of course, tongue in cheek and isn’t recommended). But just because you can lose weight in this unhealthy way, it doesn’t mean you should.

The real question is “How quickly should you lose weight?”.

And the answer to this question is “it depends”!

What does it depend on?

How quickly we lose weight depends on individual differences. Factors like genetics and ethnicity play a part, as does how our fat tissue responds to exercise.

If we were to perform an experiment and strictly control the exercise and diets of 10 people for the same amount of time, they would all see slightly different results. Some would lose more weight, some would lose less, but most people would be somewhere in the middle. This is because we all respond at different speeds to the same inputs.

So, if you’re doing the same amount of exercise and eating the same foods as your friend but they’re losing weight quicker than you, it’s nothing to worry about. In fact, this is quite normal – so don’t let it distract you from your end goal.

You’re not failing or doing something wrong. Science simply means that some of us lose weight quicker than others.

Long-term, sustainable weight loss

In this blog, I’m not talking about how quickly you can lose weight from short-term body transformations or yo-yo diets.

When I work with my clients, we’re aiming for sustainable weight loss that we can maintain in the long term. If you’re here looking for short-term fixes, you’re in the wrong place.

My answer to ‘how quickly should you lose weight?’ is based on how quickly you can continue to lose weight steadily and safely overtime without falling off your plan.

If you find yourself continually falling off-plan, it’s likely that you’re trying to do too much too soon and need to slow down to make progress.

I realise “it depends” is a bit of a flaky answer to “how quickly should I lose weight?”. So, let’s look at what you need to do to lose weight with some average numbers as a guide.

To lose weight sustainably, you need to be in a calorie deficit.

Although you may hear or read otherwise, this is the single most important factor to consider.

What’s a calorie deficit?

In a nutshell, a calorie deficit is when you’re expending (burning off) more calories than you’re consuming (taking in).

But getting the balance right is important. If your calorie deficit is too small, you may not maximise your results. If it’s too big, you won’t be able to maintain your progress.

If you eat too little (i.e. your calorie deficit is too big), you’re likely to have no energy, be in a bad mood and struggle to sleep. You won’t be able to escape your hunger and your body will react by overpowering your desire to restrict what you’re eating.

In 99% of cases, this will result in you breaking your plan. Even if you’re in the 1% that can maintain your progress in this way, it quite simply isn’t healthy.

As a general starting point, to lose weight and maintain your progress, I suggest the difference between your calorie intake and output should be no more than 500 calories a day. And, for sustainable results, less than 500 calories a day is probably better.

What does this mean in terms of weight loss?

If we took the same 10 fictional people from earlier in the blog and controlled their exercise and diet again, putting them in a 500-calorie a day deficit, we could expect them to lose on average 0.5% of their total body weight a week. Again, this is an average and some could lose more, some could lose less.

How do you keep to a 500-calorie deficit?

You could do an hour or so of exercise a day to burn off the 500 calories, or you could eat 500 fewer calories.

But, to maintain your weight loss in the long-term, a combination of both is the best way forward.

Expending 250 calories from increased physical activity and consuming 250 fewer calories through food and drink would be a great place to start.

Your progress often won’t make any sense

Bear in mind that, at times, your weight loss progress might not make any sense. This is perfectly normal and to be expected.

Don’t let it distract you from your goals or cause you to give up.

You may have eaten well all week and put on weight or eaten junk food all week and lost weight. But this doesn’t mean your plan isn’t working.

Your body will respond to exercise and dietary changes at different speeds at different times. What’s important is that you stick with it and keep to your behaviour goals, e.g. keeping to a 500-calorie deficit.

You may even find you need to take it a bit slower to see sustainable results and adapt your calorie deficit to 400 calories, for example.

But, if you let time take its course and have a little patience, you will see progress and you will lose weight.

Essentially the answer to “How quickly should I lose weight?” is:

The speed at which you can maintain your weight loss progress without breaking your plan.

Further Information

For more information about short-term body transformations, check out my article on 'Why 30-day Body Transformation Challenges Could Be Holding You Back'.

To learn more about how slowing down may help achieve your goals, check out my article 'If I Could Only Give You One Piece Of Advice'.

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How quickly can I lose weight?

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