What is a calorie and how many calories should I eat to lose weight?

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  • To lose weight, you need to burn more calories than you eat. Sounds easy, right? But what is a calorie and many calories should you eat to lose weight? Here's how it works.

    If you want to know how to lose weight fast, firstly don’t imagine you’re going on a diet. The word conjures up images of restrictions and prohibitions around all the foods you love and can set you up for failure before you’ve even started. ‘Oops I’ve eaten a chocolate biscuit. It’s all over, I’ll finish the packet.’

    Instead imagine you are embarking on a lifestyle change, one that is going to make you feel healthy in your soul, great in your body, gorgeous in your clothes and more confident about yourself.

    One of the simplest methods of how to lose weight is to count calories. This way, you can still make allowances for the treats you love and factor them into your total calorie intake for the day. The average woman needs to eat around 2000 calories to maintain her weight and around 1500 calories a day to lose weight.

    If you want to know how to lose weight, you just need to burn more calories than you eat.

    What is a calorie?

    A calorie is simply a unit that measures the energy contained in food and drink. Calories are printed on the packets of pretty much all foods and drinks (and if they aren’t, it’s easy to look them up). You can tot them up throughout the day and work out where you are without going over your desired amount.

    How to lose weight: how many calories should I eat to lose weight?

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    How many calories should I eat a day to lose two pounds a week?

    To lose one pound per week, you need to eat 3500 calories less than you normally do each week – or 500 calories less per day. This number is the same for everyone, regardless of weight. A pound of fat is equal to about 3,500 calories, so everyone must burn 3,500 more calories than they consume each week to lose a pound of fat.

    To lose two pounds per week, you’ll need to double that.

    There are many easy ways to do this.

    1: Use a smaller plate. Putting 25 per cent less food on your plate at lunch and dinner time is an easy way to reduce portion sizes.

    2: Put one quarter back. You’ve filled your bowl with cereal/pasta/rice. Now take away a quarter and eat what’s left. Are you satisfied at the end? You’ve just reduced your portion size. It may feel harder at first, but your stomach will start to shrink over two to three days and will quickly readjust to feel satisfied with a smaller amount of food. Try smaller meals with just 200 or 300 calories for a tasty, light lunch.

    3: Eat more protein. Protein is filling, good for you and helps to reduce your appetite, fighting off those food cravings. Not only that, it actually increases your metabolic rate, meaning your body starts to burn through calories faster. For high protein foods, think eggs, tuna, nuts, chicken, fish, yoghurt, tofu, granola, even cheese and (yes!) peanut butter!

    4: Avoid taking in unnecessary calories from sugary drinks such as sodas, fruit juices and milkshakes. Your body doesn’t register liquid calories in the same way as it does food, so it doesn’t feel full up after ingesting all these calories – and the added sugar is absolutely unnecessary in anyone’s diet.

    5: Drink more water. Drinking around eight glasses a day keeps your body nicely hydrated so that it’s running efficiently and that alone can help you burn 96 more calories a day. It’s also a good idea to have a glass before a meal as it will help to fill you up and aid digestion. Drinking plenty of water also helps to prevent fluid retention, as your body starts to feel confident that you are providing it with enough and lets the excess fluid it’s been holding on to – go.

    6: Reduce your intake of carbs and sugars. We’re not suggesting you cut them out altogether. The NHS positively recommends them. Starchy foods, such as bread, rice, potatoes and pasta, provide a slow and steady release of energy throughout the day. But make sure you choose the whole grain versions – and enjoy potatoes with their skins on. This will not only add fibre to your diet, which helps to keep things moving (exactly what you want to get rid of those unwanted pounds) it also helps to make you feel full.

    7: Increase your fruit and veg: Try to reduce the amount of carbs in your diet by increasing the amount of salad or veg on your plate, ensuring you get your five-a-day. When making a lunch or dinner, the ‘thirds’ rule is best: one third protein, one third veg and one third carbs. Remember, when bread enters your system, it pretty much turns back into dough in your stomach and this is hard for your body to digest. Help it along with plenty of fresh fruit or veg, they’re packed with nutrients but not many calories, so tuck into them as often as you can!

    How to lose weight: how many calories should I eat to lose weight?

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    Daily calorie intake calculator

    Many people keeping an eye on their calories use a calorie intake calculator to help them.

    The Harris-Benedict equation is the most popular one. Stand back, it looks complicated but is actually pretty simple once you do the maths.

    To work out how many calories you need for weight loss, you work out your BMR – Basal Metabolic Rate. Here’s how you do it:

    Your BMR = 655 + (4.35 x your weight in pounds) + (4.7 x height in inches) – (4.7 x age in years)

    You just need to plug in your age, height, and weight. The number you get at the end is the total number of calories you need each day to exist.

    So, a 40 year old woman who is 5ft 5ins and weighs 150 lbs has a basal metabolic rate of 1378.

    Next, you need to work out your activity factor. Your activity factor is the amount of exercise you do on a daily basis.

    Most people have an activity factor of 1.5, but you can calculate yours by looking at the factors below:

    Sedentary: Minimal movement, lots of TV watching, reading, etc. Activity factor = 1.4
    Light activity: Office work, less than one hour of moderate exercise/activity during the day. Activity factor = 1.5
    Moderate activity: Light physical exercise/manual labour during the day, plus a more active lifestyle. Activity factor = 1.6
    Very Active: Active military, full-time athlete, hard physical/manual labour work. Activity factor = 1.9

    Choose your activity factor and multiply that by your BMR:

    So 1.5 x 1378 = 2,067

    This number is the number of calories you need to eat each day to maintain your weight. To lose weight, you need to eat between 500 or 1000 calories less than this, depending on whether you want to lose one or two pounds a week.

    How to lose weight: how many calories should I eat to lose weight?

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    How many calories should I eat to lose weight with exercise?

    The average person burns around 1800 calories a day doing absolutely nothing. According to the Healthy Eating Guide, sitting burns an estimated 75 calories per hour.

    A sedentary woman aged 19 to 30 burns 1,800 to 2,000 calories daily, while a sedentary woman aged 31 to 51 burns about 1,800 calories per day.

    An active woman between 19 and 30 burns about 2,400 calories per day, while an active woman aged 31 to 51 burns about 2,200 calories.

    The number of actual calories burned, of course, depends on your body composition, weight and metabolism – and here’s where things get a bit complicated.

    For example, a 125-pound person will burn just 120 calories during a 30-minute walk at 3.5 miles per hour, while a 185-pound person will burn 178 calories during a walk of the same speed and length.

    If the same two people swam the front crawl for 30 minutes, the 125-pound person would burn 330 calories, and the 185-pound person would burn 488 calories.

    So, a heavier person will burn more calories than a slim person, but muscle burns more calories than fat. If a muscular person and an overweight person exercise at the same intensity, the muscular person will burn more calories than the overweight person.

    For simplicity, we will use an average weight person exercising for 30 minutes at a time to illustrate which activities are best at burning calories:

    Aerobics – 350 calories
    Skipping – 390 calories
    Rowing – 370 calories
    Skiing – 360 calories
    Running – 300 calories
    Swimming – 300 calories
    Playing tennis – 200 calories
    Walking – 150 calories

    READ MORE: 15 minute workouts to improve your strength, fitness and balance

    How to lose weight: how many calories should I eat to lose weight?

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    Seven calorie counting weight loss tips

    If you choose the calorie-counting method to help you lose weight, there are lots of ways to make things nice and easy to help you along:

    1: Use a Fitbit: Fitbit provides a great ‘calorie burn’ estimate, taking into account your BMR, the activity recorded by your tracker and any activities you log manually. Your tracker’s calorie count will reset each night at midnight and begin counting immediately thereafter. BMR is the reason your tracker starts the day with calories already burned — you still burn calories in your sleep.

    2: MyFitnessPal is one of the most popular calorie counters right now. It tracks your weight and calculates a recommended daily calorie intake. It also contains a well-designed food diary and an exercise log. If you’re using a fitness tracking device, MyFitnessPal can usually sync with it and then include the data in the exercise log.

    The app tracks your progress towards your goals and offers chat forums with fellow users. These include conversations, recipes, tips and personal success stories. MyFitnessPal’s nutrition database is huge, containing over five million foods. You can also create custom foods and dishes or download recipes from the internet.

    MyFitnessPal also has a barcode scanner, so you can also instantly enter the nutritional information of some packaged foods.

    3: Bulk prep meals in advance. This will save time when it comes to working out the calories. Set aside a few hours once a month to put on your chef’s hat and have some fun cooking meals you like that can be portioned up and frozen. We have plenty of low calories meals to inspire you, including our 160 family meals under 500 calories, meals under 300 calories, and lunches under 200 calories just to get you started.

    4: Lose It is one of the apps that puts the emphasis firmly on losing weight, as the name suggests. Like its rivals, it starts by getting you to set a goal: using your current and target weights, height, gender and desired pace of weight loss to assign a daily “budget” for your food intake.

    Graphs on your intake, nutrients and steps are very clear, while the process for logging your meals, snacks and exercise is quick and easy too, whether you’re searching for ingredients or scanning barcodes. The ability to browse menus from popular restaurant brands, from KFC to Nando’s, is also handy.

    They have an active chat community and a tab called ‘challenges’, where you can participate in challenges or make your own.

    Lose It is free at its basic level, but its premium tier costs £29.99 a year. It offers more tracking (hydration, sleep, body fat etc); more detailed nutritional reports; more features for meal and exercise planning, and a wider range of challenges including the ability to create your own.

    5: Get portion savvy. Even if you can’t or don’t want to tally the calories you eat at every single meal or snack, portion control is an easy way to help you consume fewer calories. Think of a tennis ball. It’s the equivalent of the recommended portion for items like pasta, cereal and yogurt.

    6: Don’t eat straight out of the container. It’s a recipe for mindlessly overeating. Instead, measure a serving size of whatever you’re noshing on — almonds, soy chips, or other snacks — and put it on a plate or in a bowl.

    7: Use smaller plates. This really is a great way to lose weight. Trick your mind into thinking that you have more food by downsizing your large dinner plate for a smaller, salad-sized one. A healthy portion can look tiny on a huge plate but will seem more normal when you shrink its surroundings. And spoil your appetite with nutritious low calories snacks. Try eating celery sticks with peanut butter an hour before lunch or dinner. You’ll eat less at the meal and feel more satisfied later.

    How many calories do I need to eat when breast-feeding?

    During the first few months of breastfeeding, your body needs an extra 500 calories a day in order to keep up your milk supply for your baby.

    Breastfeeding mums will often find they are incredibly thirsty and craving sugar, as the body demands you eat more fruits (rich in vitamin C), magnesium and protein to keep your energy levels up while nourishing your baby.

    It’s perfectly safe to watch the calories while breastfeeding, just make sure your total caloric intake doesn’t dip below 1,800 calories per day and you keep eating a wide variety of nutritious foods.

    Calorie counting: is it for you?

    Calorie counting might not be for everyone, but it is an easy-to-follow plan for those who want to restrict their calorie intake and exercise more to help them lose weight.

    Results can usually be seen pretty quickly and counting calories provides an easy structure to follow for those who don’t want to embark on faddy diet plans.

    Tracking calories is also a great way of becoming aware of bad habits (ie eating too many high calorie, sugary foods) while encouraging low-calorie, healthier alternatives.