How to lose 100 pounds

In its simplest form, weight loss comes down to a short equation: calories in – calories out. A calorie is a unit of energy. ‘Calories in’ represents the energy that you introduce into your body via the food that you eat. ‘Calories out’ represents the energy that you burn naturally throughout the day, and when you exercise.

To lose weight, the result of this equation needs to be a negative number. This means you need to consume fewer calories than you burn, also known as a caloric deficit. Doing so forces your body to use its fat stores as a source of energy.

The number of calories that a person should aim to consume will depend on their age, gender, height, weight, activity levels and overall goals. Because of this, the calorie requirements of two people can differ greatly. You can use the calculator below to estimate the number of calories that 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 25 year old lady who weighs 255 pounds, is 5 feet 7 inches tall and exercises 4 times a week will need to consume approximately 3000 calories to maintain her weight, 2400 calories to lose weight and 1800 calories to lose weight fast.

It is generally advised that you shouldn’t consume fewer than 1000 calories without medical supervision, because doing so can lead to health problems. Also, consuming too few calories can cause your metabolism to slow down. It is therefore important not to starve yourself because this can slow down weight loss progress dramatically.

Your diet is extremely important when it comes to weight loss. Eating the correct types of food can help you to minimize your overall calorie intake and therefore speed up the rate at which you lose 100 pounds.

Ideally, the first thing that you would want to do is get a rough idea of how many calories you are consuming per day. You can do this by using an app like myfitnesspal, or by writing down everything that you eat on an average day and then referring to a website such as to get the nutritional information of various foods.

For example, consider the meal plan below.

Breakfast – 2 medium butter croissants and a glass of orange juice – 574 calories

Snack – 1 cereal bar – 139 calories

Lunch – 1 chicken & cheese sandwich and a can of cola – 767 calories

Snack – 1 pack of tortilla chips and a chocolate bar – 379 calories

Dinner + dessert – 1/2 a 14 inch pizza with cheese topping and vanilla ice cream – 1332 calories

Total: 3191 calories

We tend to underestimate the number of calories that we consume and people are often shocked when they learn just how many calories they eat each day.

Once you know how many calories you eat on average, you can begin making food substitutions to reduce this number. Here are some tips to do this effectively.

Eat plenty of vegetables

Vegetables should make up a large part of your diet because they are some of the most nutrients dense foods that you can eat. Most vegetables are made up of more than 80 – 90% water, and because water has 0 calories, vegetables are very low in calories as well.

For example, a cup of boiled kale only has 36 calories. Comparatively, just one slice of a 14 inch pizza has 285 calories. This means that you would have to eat 8 cups of kale to get the same amount of energy that the slice of pizza provides.

Vegetables are also a rich source of dietary fiber. This is especially true for crunchy ones such as artichokes, parsnips and Brussels sprouts. When you eat fiber, it swells up and adds bulk to your stomach. This can help decrease subsequent food intake.

This study found that making a simple change and increasing fiber intake can help with weight loss efforts. Most people don’t get enough fiber in their diet; eating plenty of vegetables is an easy way of increasing your intake.

Vegetables also provide potent doses of crucial nutrients. The cup of cooked kale for example provides almost all of your daily requirement of vitamin C. Some vitamins and minerals are necessary for optimal metabolic health and eating vegetables can help prevent deficiencies.

You should aim to eat a variety of vegetables, including leafy greens such as spinach, root vegetables like beets and fruit vegetables like pumpkin.

Because of their versatility, vegetables can be incorporated into lots of delicious recipes.

Eat some fruit

Just like vegetables, most fruits tend to be low in calories, but are rich in nutrients. They have the added benefit of being a great source of naturally occurring sugars. This comes in handy, especially if you have a sweet tooth.

You can eat a combination of both fleshy and dried fruit. There are lots of different fruits to choose from, including bananas, mangoes, apples, grapes, pineapple, dates, prunes and pomegranates.

Aim to eat 2 or 3 servings of fruit per day (if you are diabetic or very obese, check with your doctor so that he or she can advise you on how much fruit you should be eating).

Fruits can be eaten on their own as a snack, added to yogurt & smoothies or even used to prepare healthy homemade treats. For example, you can make a healthy version of ice cream using frozen bananas and a few other ingredients.

Increase your protein intake

Out of the 3 macro-nutrients (the other two being fat and carbs), protein has the highest satiety. This means that it is the most filling.

Eating protein can help on both ends of the calories in – calories out equation. This is because it can help you to eat less, but also assists with calorie expenditure.

This study found that increasing protein intake from 15% to 30% of total calories resulted in 441 fewer calories being consumed per day. This is a significant amount. Eating a protein rich breakfast has been shown to help regulate appetite hormones and suppress subsequent food intake in studies such as this and this.

Another study found that a high protein diet reduced obsessive thoughts about food and late night desire to snack in overweight & obese men.

And this study found that increased protein consumption resulted in increased energy expenditure.

When you are in a calorie deficit, your body will burn both fat and some muscle tissue for energy. A protein rich diet combined with weight training helps you to retain as much muscle mass as possible. This is ideally what you want when losing weight – burn fat whilst preserving muscle.

There are many high protein foods to choose from, including eggs, legumes, fish, meat, nuts, seeds and dairy. Protein shakes are also an easy way to add protein to your diet. As a general guideline, you should aim for 25 – 30% of your total calories to come from protein.

Don’t fear fat

Eating fat doesn’t make you fat. Eating more calories then you require does.

It is true that weight for weight, fat has more than twice the amount of calories that protein and carbs have. For this reason people tend to avoid fat when trying to lose weight. But this should not be the case because you need fat in your diet. What is important is the type of fat that you eat.

The fat that is obtained from foods that are as close to their natural state as possible can be highly beneficial for weight loss. This includes foods such as avocados, nuts, seeds, coconut oil and fatty fish. These foods are high in Omega-3’s, monounsaturated and polyunsaturated fats.

In this study, participants consumed one of three lunches – avocado free, avocado inclusive and avocado added. The avocado added meal increased satisfaction by 23% and decreased the desire to eat by 28% when compared to the avocado free meal.

Fatty fish is rich in fat and protein, which makes it a great weight loss food. And coconut oil has a thermogenic effect, so eating it may increase energy expenditure. It has also been shown to reduce belly fat and waist circumference; this makes it the best type of fat to cook in.

The types of fat rich foods that you want to completely avoid or reduce consumption of are those that have fat artificially added to them. This includes things like cakes, cookies and pastries. These foods are highly addictive and energy rich but provide very little nutritional value.

Eat the right type of carbs

Numerous studies have shown that low carb diets are very effective for weight loss. Reducing your carb intake can be a strategy that you can use to shorten the amount of time it takes you to lose 100 pounds.

A general guideline is to consume 50 – 150 g of carbs per day. Individual carb requirements vary from person to person, depending on activity levels, metabolism and age.

Like with fat, most of the carbs that you eat should come from foods that are as close to nature as possible. These include oats, sweet potatoes, beans, quinoa, lentils, brown rice and vegetables. The carbs obtained from these foods are known as complex carbs and they provide a slow release of energy.

The type of carbs that you want to avoid are refined carbs, especially those that have added sugar. Unlike complex carbs, these are digested very quickly and provide large bursts of energy. They can cause dramatic spikes and dips in blood sugar & insulin levels which makes you crave more food soon after eating them.

Junk foods such as cakes and cookies are usually high in both processed carbs and fat which is why reducing their intake as much as possible is very important.

Drink water

Because water has 0 calories, it is a very weight loss friendly beverage. You can drink lots of it without having to worry about calories.

Studies have shown that drinking water benefits weight loss.

In this study, participants followed a calorie deficit diet. Some participants also drank 500 ml of water before each meal. After 12 weeks both groups ended up losing weight, but the water consumers lost an average of 2 kg (4.4 lb) more.

Another study found that adults who drank water before breakfast consumed 13% fewer calories.

Additionally, water consumption has been shown to boost metabolism slightly, as seen in studies such as this and this.

People often mistake thirst for hunger and instead of reaching out for a glass of water, they reach out for food instead. The next time you feel like eating something, drink a glass of water and then determine whether you really need to eat or not. Another handy tip is to have a glass of water before each meal as this might help you to eat less.

In place of ordinary water you can occasionally drink carbonated water, homemade coffee and tea.

The beverages that you definitely want to reduce consumption of are those that have been sweetened with sugar. This includes sodas and even some fruit juices. The problem with these beverages is that they are high in calories but the energy that you get from them is not well compensated for.

When you eat solid food, your stomach and brain register this and therefore know that you should feel less hungry. Unfortunately this process doesn’t work as efficiently when you drink sugar sweetened beverages, meaning there is a high possibility that you end up consuming more calories than you should. Studies have found that there is an extremely high correlation between the consumption of sugar sweetened beverages and obesity.

You should also consume alcohol in small amounts because regularly drinking large amounts of alcohol can negatively affect weight loss.


Now that you have a good idea of the types of foods that you should be eating, let’s revise the meal plan above to include more nutrient dense foods.

Breakfast – 2 large boiled eggs, a cup of cooked oatmeal and a large banana – 441 calories

Snack – an avocado – 322 calories

Lunch: grilled chicken breast with steamed vegetables – 394 calories

Snack –  1 cup of Greek yogurt with 1 cup of strawberries – 275 calories

Dinner + dessert – 1 cup of cooked lentils, 1 cup of boiled vegetables and 2 pieces of dark chocolate –  440 calories

Total: 1872 calories

Notice that we haven’t significantly changed the quantity of food in the meal plan. But by making some healthy substitutions, we were able to reduce energy intake by more than 1000 calories!

Use a similar approach to your own diet and try and reduce calorie intake by eating more natural and wholesome food. When you eat your food, it is important to eat mindfully. This lets you appreciate each bite and helps prevent overeating.

Remaining in a calorie deficit will cause you to lose weight. After a while, the rate at which you lose weight might begin to slow down. If this happens, you may want to reassess your calorie requirements once again. Losing 100 pounds is a lengthy process so it is important to remain patient and not get discouraged if progress slows down.


Diet is definitely the most important aspect of losing large amounts of weight. However exercise also helps. The more active you are, the more calories you burn. A person who goes to the gym 5 times a week will burn far more calories than someone who does not exercise.

Exercise helps you to create a larger net calorie deficit. For this reason, you should try and do 30 minutes of exercise 3 to 4 times a week at minimum. This can be anything that you enjoy, including swimming, cycling, jogging, martial arts and even dancing.

If you don’t already exercise, you can start off by simply taking a 20 – 30 minute walk a few times a week. As your fitness improves, you can increase the intensity and duration.

Cardiovascular activity can help you burn calories. In particular, high intensity interval training (HIIT) has been shown to be very effective. This involves doing short bursts of intense activity followed by longer periods of the same activity at a more comfortable pace.

For example you can sprint ‘all out’ for 20 seconds and then jog at a comfortable pace for a minute. Repeat this cycle for 15 to 20 minutes. Studies have found that HIIT increases fat burning and metabolism. It is not meant for everyone though. If you are just starting out exercising, build up your endurance before trying out HIIT.

As mentioned above, weight training is important too because it helps you to retain muscle mass. Which brings on another extremely crucial point – don’t rely solely on your weighing scale to monitor your progress. This  is because just like fat, muscle has mass. However it is much more compact and therefore takes up less room in your body. But when you step on to an ordinary weighing scale, it is unable to differentiate between fat and muscle mass.

This is why you should also use body measurements to monitor progress. If your body fat percentage goes down over time and your clothes feel looser but the number on the scale hasn’t changed much, don’t fret. All this means is that you have built muscle and burnt fat, which is a step in the right direction.

Your goal shouldn’t be just to lose 100 pounds but to also have a healthy body composition.


Losing 100 pounds will take some time but can definitely be achieved through a combination of diet and exercise. Once you lose the weight, it is important to continue eating healthy foods and exercising regularly, so as to prevent the weight from creeping back again.

Are olives fattening or good for weight loss?
Are lentils fattening or good for weight loss?