How Many Calories do You Really Need? (2024)

By Dietitian Juliette Kellow BSc RD

The number of calories you can eat to lose weight depends on 6 factors:

1. Whether you are male or female
2. How much you weigh now
3. Your background activity level
4. How old you are
5. How tall you are
6. How quickly you want to lose weight (or how hard you want to make it!)

Each of these 6 are explained below, along with charts showing the calories needed for weight loss at different rates, so you can work out a ball-park figure for yourself.

1 - Male VS Female Calorie Needs

These calculations are for a man and a woman of the same age (40), weight (13 stone), height (5'6) and background activity level (moderately sedentary), to lose a pound, one and a half pounds or 2 pounds a week.

The simple fact is that men burn more calories than women, even when all other factors are the same. This is because men have more muscle than women - and muscle burns calories even while you are asleep.

2 - Calories Based on Your Weight Now

Your Starting weight has a big impact on the how many calories you can eat to lose weight.

Calories by Start Weight for Women

This table is based on a 30 year old woman who is moderately sedentary and 5'5 in height.

*1100 calories per day is the minimum recommended by wlr for maintaining a healthy diet with sufficientnutrients and variety of foods.

You can use the lose a stone calulator to see an estimate of how long it would take for you to lose a stone, based on your gender, current weight and height.

Calories by Start Weight for Men

The men's chart is based on a moderately sedentary 35 year old man of 5'9 tall.

The number of calories required for you to lose weight gets loweras your weight goes down.

People sometimes blame some variation of 'starvation mode' when the number of calories needed to maintain their 2lb a week weight loss goes down. But this doesn't happen when you are losing weight at a maximum 2lbs a week.

As you can see from the chart, it's just that you naturally need fewer calories at a lower weight.

3 - Your Background Activity Level

In this chart the woman is age 30, 5'4 tall and weighs 13 stone 3lbs. The man is 38, is 5'10 and weighs 14 stone 7lbs.

Background activity level is your average level of day-to-day activity. These calculations exclude extra calories for specific periods of exercise.

If you do exercise that is not accounted for in your background activity level, you should add the extra calories burned to your calorie allowance for that day.

What’s Your Level?

Choose the level that most closely resembles how active you are on normal days.

• Very Sedentary – you don’t move around very much, sitting or lying down for most of the day, maybe due to ill health or a disability.
• Moderately Sedentary – you work in an office or other job that doesn’t involve much physical movement like driving. Or stay at home with relatively small amounts of time doing light household tasks.
• Moderately Active - you are a parent looking after home and young children, or maybe doing a job that requires a fair amount of moving around but not normally a big physical effort, like nursing, shop or warehouse work.
• Very Active - you are someone doing heavy physical work, for example a bricklayer or agricultural worker doing strenuous work on their feet for most of the day

4 - How Old You Are

As we get older our calorie needs slowly decrease. So you can eat more calories if you're a 28 year old trying to lose weight, than you can if you're 48.

Our examples are a female of 5'7 weighing 14st 8lb and a male of 5'11 weighing 16st 8lb.

You canuse the wlr tools to see how many calories you can eat to lose weight atyour age, height and weight. Try it freeto get the number that's right for you.

5 - How Tall You Are

To those of us below average height it doesn't seem fair that taller people can eat more calories and still lose weight. We console ourselves with the thought that great things come in small parcels!

Our examples are a woman age 40, who weighs 13 and a half stone, and a man of the same age weighing 15 stone.

6 - How Quickly You Want to Lose

As you can see, the faster you want to lose weight, the fewer calories you can eat day to day.

There are diets that claim you can lose half a stone in a week, and it's not impossible if you starve yourself.

The problem is that most of that initial fast wieight loss will be water and energy that was stored up in your muscles - not much actual fat.

Worse than that, you'll put yourself through a nasty regime for very short term losses.

You won't continue to lose half a stone a week, and unless you maintain a calorie intake lower than that required for a 2lb a week loss (some form of fasting or extreme sessions of intense exercise) your weight loss will settle at around a maximum of 2lbs a week.

Research shows that even low carb, ketogenic diets produce high weight loss at the start, end up producing similar amounts of weight loss to a normal low calorie diet by the time you get to 3 or six months.

So why put yourself through that?

In any event, in our experience people mostly want to lose fat from around their belly - not water weight that could make their muscles look a little bigger.

Our Advice

• Choose a rate of loss that provides you with a calorie allowance you can live with for long enough to reach your weight loss goal
• Try out different calorie levels to see what's right for you
• Try and increase your background activity level, or add in some exercise sessions (brisk walking will do the trick) to incease the calories you can eat whilst continuing to lose weight
• Try some resistance or weight training exercise to build up your muscle. (The reason men burn more calories than women is because they have more muscle)
• Log the calories you consume on a regular basis to keep on track with your weight loss

How Many Calories Do You Need?

You can get the right number personal to you and how much you want to lose, plus the calorie counting tools that make it easy to keep track and lose weight. You cantry wlr free.

Take our FREE trial »

Calorie Allowance Q & A

Answered by Dietitian Juliette Kellow BSc RD

To give you an idea of the kinds of things that affect your calorie needs, these are some of the questions that have been asked by wlr users.

Q: My friend and I are the same height but I’m 2 stone heavier. We’ve both joined Weight Loss Resources and chosen to lose 2lb a week.

Can you explain why I’m allowed more calories a day than my friend? Surely the heavier you are, the fewer calories you need to lose weight

A: This confuses a lot of people but in fact, the heavier you are, the more calories you can have each day while still losing weight.

Let me explain ...

That extra 2 stone you’re carrying is actually equivalent in weight to 28 packets of butter. Now imagine carrying those packets of butter around with you everywhere you go – up and down the stairs, to the local shops, in and out of the car, into the kitchen to make a cup of tea.

Hopefully, you can see it takes a lot more energy simply to move around when you’re carrying all that extra weight.

As a consequence, because you are heavier than your friend, you need more calories in a day to maintain your weight. In turn, this means you will lose 2lbs a week on a higher number of calories than your friend.

However, as your weight drops, your calorie allowance will also drop slightly as you’ll have less weight to carry around.

This is why you should regularly update your weight, wlr will automatically adjust your daily calorie allowance for you.

Q: I broke my shoulder in January and so haven’t been able to do any exercise. I’ve gained so much weight and now weigh around 15 stone. What diet should I follow, bearing in mind I’ve still got a long way to go before I’m fully mobile?

A: It’s still possible to lose weight without exercising, although it will take you a little longer.

Here’s how it works ...

Your weight – and particularly the amount of fat you have stored in your body – is simply a reflection of the amount of calories you take in through eating and drinking and the amount of calories your body uses up every day.

When the amount of calories you take in equals the amount of calories you use up, your weight stays the same.

When you take in more calories than you use up, the extra calories are stored as fat and you gain weight.

In contrast, when you take in fewer calories than you use up, your body starts using up its fat supplies and you lose weight – and of course this is the situation you want to be in.

As you’ve already pointed out, until you’ve fully recovered from your accident, you’re going to find it hard to use up more calories by exercising.

So, for the time being it’s really important to concentrate on taking in fewer calories by watching what you eat and drink.

Update your activity level and wlr will work out a suitable daily calorie allowance for you to lose weight at your chosen rate, taking into consideration that you’re not very active.

Don’t be surprised if you’re actually allowed a slightly higher calorie intake than in the past – because you’ve gained weight, your body has to work harder to move around and so you’ll be able to have more calories and still lose weight.

Once you’re able to exercise again, wlr will be able to work out exactly how many more calories you can have each day, depending on the exercise you’ve done. Good luck.

Q: I’m 52 year’s old, 12st 6lb and 5ft 3in and over the years have been on many diets. I’ve lost weight each time but then put it back on and more. Now I’m finding it difficult to lose weight at all – the calorie allowance on most diets allows me more than I eat to maintain my weight, let alone lose any.

Have I damaged my metabolic rate by frequently dieting so that now I need to eat less and less in order to avoid putting on weight, and if so, what’s the solution?

A: For years it was thought that yo-yo dieting damaged our metabolism beyond repair. But fortunately, years of research have shown this is unlikely to be the case.

I suggest you start by reading the feature on starvation mode. This explains what happens to your metabolism when you cut calories dramatically. As you’ll discover from this piece, it’s likely your metabolic rate is much lower now than it was in the past, because every time you’ve lost weight, you’ve lost muscle as well as fat. In contrast, every time you’ve put on weight, you’ve only regained fat – and it’s the amount of muscle we have that helps determine our metabolic rate.

With regard to the number of calories you need to lose weight, I’ve calculated your Basal Metabolic Rate (BMR) to be 1,500 calories a day. This is the number of calories your body uses up simply to keep it ticking over, for example, to keep you breathing and to keep your heart beating. All activity you do on top of this will increase the amount of calories you use up – even things like talking, standing and sitting.

This means you should easily lose weight on a calorie intake of 1,500 calories a day. Indeed, for someone of your age, height and weight, WLR recommends a daily calorie intake of just over 1,700 calories a day to help you lose 1lb a week.

As you’re finding it so difficult to lose weight, I suggest you keep a strict food diary and get into the habit of weighing everything you eat for a week or two so that you can be accurate about your portion sizes. This should help you to stick to your daily calorie allowance.

It’s also important to make sure you eat enough to ensure you burn fat rather than muscle. Exercise too will help the process along. Combine all these things and hopefully, you should see the weight start to come off slowly but surely – and this time you want to keep it off for good.

Q: I’ve opted to lose 1½lb a week with WLR but am finding it hard to stick to the same calorie allowance every day. During the week I tend to have less calories than I’m allowed, but at weekends I find I’m usually over my calorie allowance.

Is it OK to bank any calories that are left at the end of the week and have them at the weekend when I’m more likely to go out for a drink?

A: Absolutely! Generally, we talk about daily energy requirements and so most diets break calorie allowances into daily blocks. However, it’s just as valid to use other periods of time such as weeks, or even months.

The key to losing weight is to take in fewer calories than you need for as long as it takes to reach your target, aiming for a loss of ½-2lb a week.

It’s fine to multiply your daily allowance by seven to work out a weekly calorie allowance and then allocate more calories to some days than others.

For example:

If you’re allowed 1,250 calories a day, you could multiply this by seven and allow yourself 8,750 calories for the week, allowing say 1,100 calories each day from Monday to Friday and 1,625 calories on both Saturday and Sunday.

Fortunately you don't have to work it all out for yourself, the wlr calories history report does this for you.

Q: I stick to 1,000 calories a day but do very little exercise as I have sciatica and arthritis. I’ve lost just over a stone since joining WLR and am enjoying the diet. But I’m worried I’ll soon stop losing weight because I’m not very active. My GP thinks it’s highly unlikely that I’ll carry on losing weight. Should I be referred to the hospital dietitian?

A: Hold on a minute! You’re worrying about a problem that hasn’t even happened yet.

As you’ve already lost a stone, are continuing to lose weight and are enjoying the diet, I suggest that for the time being you carry on with what you’re doing.

After all, it’s clearly working!

Many slimmers experience a plateau from time to time, where weight loss stops for a week or two, despite them sticking rigidly to their diet.

But this seems to resolve itself quickly enough so that the pounds start dropping off again.

Should you reach this point (and there’s nothing to say that you will), I suggest you take a close look at your food diary and go back to weighing and measuring your portions – it’s easy for serving sizes to creep up without even noticing.

Bear in mind that as you lose weight, the amount of calories you need drops very slightly, simply because you have less bulk to carry around and so don’t need quite as much energy.

Finally, if you do find you come completely unstuck (which I’m sure won’t happen), that might be the time to be referred to the hospital dietitian.

In the meantime, I suggest you make it your aim to prove your GP wrong!