How long does it take to lose weight?

In order to lose weight, you need to burn more calories than your body gets from the food that you eat. This is known as a calorie deficit and forces your body to use its fat stores as a source of energy. Your main aim when it comes to losing weight  should be to burn fat whilst retaining muscle.

It is important to note that weight loss is not a straightforward linear process. Your body is very dynamic and will change in the way that it functions as you start to lose weight.

The number of calories that you need to consume in order to lose weight depends on your weight, height, age, gender and how active you are. You can use the calculator on this page to get a rough estimate of the number of calories you should be consuming.

Gender Age Weight Switch to lbs Height Switch to feet and inches Activity Level

This calculator will never show a number below 1000 calories per day. Please speak to a qualified health professional before attempting to eat less than that.

For example, a 35 year old lady who weighs 160 pounds, is 5 and a half feet tall and exercises 4 times a week will need approximately 2200 calories to maintain her weight, 1800 calories to lose weight (approximately a pound per week) and 1350 calories to lose weight fast (approximately 2 pounds per week).

It is generally not recommended that you consume fewer than 1,000 – 1,200 calories per day, depending on your gender and body type. Doing so can not only lead to health issues but may also force your metabolism to slow down because your body tries to conserve energy. Everybody is different, so always speak to your doctor – he or she can then advise you on the minimum number of calories you should be consuming.

A healthy amount of weight to lose in a week is between 1 and 2 pounds, which equates to 4 – 8 pounds in a month. But by following a strict eating and exercise plan, losing 10 pounds in a month is possible. If you are extremely overweight, it may be possible to lose weight at an even faster rate initially.

The amount of weight that you should aim to lose will depend on your starting weight. Your BMI gives you an indication of how your weight compares to your height. It is calculated using the following formula:

BMI = ( Weight in Pounds / ( Height in inches x Height in inches ) ) x 703

A BMI between 18.5 and 24.9 is considered to be healthy and in the normal range. You should aim to lose enough weight so that your BMI fits within this range.

Here are some tips to help increase the speed at which you lose weight:

Monitor calories

Different foods have different amounts of calories in them. Those foods that are mainly made up of water, like fruits and vegetables, tend to be low in calories, whereas those that are mainly made up of fat, like nuts and seeds, tend to be high in calories.

For example, 100 g of pumpkin seeds has 559 calories but 100 g of cauliflower has only 25 calories. However this doesn’t mean that nuts and seeds should be avoided entirely; when eaten in moderation they can help with weight loss because of their high protein and fiber content (more on this later).

It is impossible to determine the number of calories you are consuming just by relying on your stomach, because both low calorie and high calorie foods can make you feel full. For this reason, it is important to keep a food diary where you record everything that you eat.

You can either just use a paper and pen or an app like myfitnesspal (which is available for both iOS and Android).

The apps are much easier to use because they keep a daily log and use an online food database to calculate the total number of calories you consume. With the pen and paper option, you will have to keep a record of all the meals that you eat and calculate the calories in them. For example:

Breakfast – 2 boiled eggs, 1/2 an avocado and a cup of green tea.

You can then use one of the many calorie counter websites out there (like or to estimate the total number of calories. 2 boiled eggs have 156 calories, 1/2 an avocado has 161 calories and green tea has 0 calories. So breakfast would be a total of 317 calories.

Once you have a rough estimate of how many calories you are consuming on a daily basis, you can then start substituting certain foods for healthier options. The first foods you should aim to replace are processed carbohydrates and junk foods, because these tend to be very high in calories but provide very little nutritional value. For example, half of a 14 inch thin crust cheese pizza has almost 1,000 calories. On the other hand, 2 roasted chicken breasts have 284 calories and a cup of steamed vegetables has 100 calories or less.

Choosing the chicken and veggies over the pizza means that you would save yourself more than 500 calories per day, whilst supplying your body with lots of vitamins and minerals at the same time.

For more information on weight loss diets, read our in-depth article here.

Eat more protein and fiber

Both protein and fiber are very filling, so eating more of them means that you are less likely to overeat. This makes a big difference in determining how quickly you start to lose weight.

A lot of studies have been carried out on protein to analyse how it fits into weight loss diets. One study found that when protein consumption was increased to 30% of total calories, 441 fewer calories were eaten per day.

This study found that overweight men on a high protein diet had fewer obsessive thoughts about food and less of a late night desire to eat than those on a normal protein diet.

Protein doesn’t just fill you up, it also boosts your metabolism slightly, helping you to burn extra calories per day.

Fiber also increases satiety. This study found that upping fiber intake to 30 g or more per day helped people to lose weight.

Foods that are high in protein and fiber include vegetables, fruits, lean meat, legumes, eggs, fish, nuts and seeds. These are the types of foods you should be eating more of whilst cutting back on, or completely eliminating processed carbohydrates.

Drink more water and fewer sugary beverages

Water is one of the best beverages to drink to lose weight. It has 0 calories, 0 g of sugar and studies have shown that it can boost metabolism slightly whilst reducing appetite. This study found that drinking water half an hour before meals increased weight loss by 44% over 12 weeks.

If you drink soda you should try and stop because it is one of the leading causes of weight gain. It is packed full of calories and sugar (an average can of cola has 100+ calories and 30+ g of sugar) but provides very little nutritional value. This is why the calories that it provides are considered to be “empty”.

When you eat solid food, the chewing together with the bulk that the food adds to your stomach sends a signal to your brain which tells it that you have eaten, so you should feel less hungry.

Many sugary drinks don’t work this way and your brain doesn’t register the calories that they provide as efficiently, which leads to extra calories being consumed.

The high sugar content causes your blood sugar to rise and fall dramatically, which leaves you feeling hungry. Additionally, a lot of the sugar in these drinks is in the form of fructose. Fructose doesn’t suppress appetite like glucose does and it leads to an increase in visceral fat.

Unfortunately diet soda does not appear to be a good replacement option either.

Fruit juice should also be drunk with caution. Whilst good quality fruit juice does provide your body with vitamins and minerals, it still is high in calories and sugar. You are better off eating solid fruit instead.

If you want to lose weight fast, start drinking more water. Tea and coffee are also fine, provided you don’t add too much sugar or cream. They are both very low in calories and the caffeine that they contain helps to boost your metabolism slightly.

Exercise more

Following a healthy diet is by far the most important aspect of losing weight, however exercising also plays a role because it helps you to increase your net calorie deficit. The more you move, the more calories you burn; a person who jogs for 45 minutes 4 times a week will use up far more calories than someone who does not exercise.

An effective form of exercise is high intensity interval training (HIIT). It involves short bursts of intense activity followed by a longer period of normal paced activity. For example, you could run on a treadmill as fast as you can for 30 seconds and then jog at a comfortable pace for a minute – repeat this cycle for 15 – 20 minutes.

Resistance training is also important when losing weight. Without resistance training, you will end up losing both fat and muscle. This will leave you looking “skinny fat” rather than lean and toned. Try train with weights at least twice a week if possible and then increase the amount that you do gradually. A protein rich diet together with resistance training will help you to retain a large amount of muscle.

Many people judge weight loss success by the numbers that they see on the scale, however you should not rely on your weighing scale alone. This is because when you train with weights, you will burn fat but may also build a bit of muscle at the same time. And just like fat, muscle has mass, but it takes up less space in your body.

So whilst you may not see the changes you had hoped for when you step on the scale, you will see them when you look in the mirror. You should therefore use a combination of a mirror, photos, fat calipers, measuring tape and weighing scale to monitor progress.


It takes time to lose weight in a healthy manner; you can expect to lose between 1 and 2 pounds per week. Changing the way your body looks does not happen overnight, but if you stick to a good eating and exercise plan, you will gradually start to see significant differences over time.

How eating cucumbers can help you lose weight
How to lose 5 pounds in 2 weeks