Healthy vs unhealthy calories. What’s makes some food healthier for us, what are macronutrients and are all calories the same?
What is a calorie?
A calorie is a unit of energy. 1 calorie will produce 4,184 Joules of energy. The actual definition is ‘The amount of heat needed to raise the temperature of one gram of water by one degree celsius’. We think of calories differently. We think of them as food we eat, how many we are consuming and how many we should have in a day. At best we see them as a source of energy.
Are all calories the same?
So if a calorie is a calorie, why does it matter what food we eat to stay healthy and energetic? Why should we eat nutritious foods? Because the body is a complex biochemical machine. It will see what form these calories come in. The digestion of food is very complex and the body doesn’t just need calories but all the nutrients that come with these calories to maintain a healthy balance.
Healthy calories are foods that provide lean protein, complex carbs and healthy fats. Unhealthy or bad calories are foods that contain virtually no nutritional benefit, often referred to as ‘Empty calories’. These can contain a huge number of calories in a small portion compared to healthier foods. You would find it easy to eat 500 calories of chips or ice cream, but hard to eat 500 calories of broccoli, even if you really liked it.
Calories in Food
Macronutrients – The largest part of our daily food intake. They are Fats, Carbohydrates and Protein and they provide us with our energy.
Fat: 9 calories per gram
Carbohydrates: 4 calories per gram
Protein: 4 calories per gram
The rest comes in smaller amounts in the form of vitamins and minerals. (Vitamins and minerals are deemed essential because they help strengthen bones, heal wounds, improve our immune system and repair cell damage.)
People will often stay away from fat when they are trying to reduce their daily calorie intake, however some fats are essential to the body, polyunsaturated fat, for example, is good for the heart. Carbohydrates offer fewer calories but refined carbohydrates, found in sweets or chocolates, don’t provide any nutritional value. Protein is essential for both weight loss and weight gain. Loss because it helps fill you up making you less hungry. It is the most filling macronutrient. Gain because its essential for muscle growth, however, if you want to gain weight, you will have to make sure you eat enough calories.
Fats
Fats come in a variety of different forms, and new research has shown that certain fats aren’t as bad for you as once thought. We can break them down into Trans fat, Saturated fat, Monounsaturated and Polyunsaturated.
Trans Fat: The one to avoid. Industrially made to help improve the shelf life of foods. The process makes the fat solid at room temperature. It is bad because it raises your ‘bad’ colhesterol and lowers your ‘good’ colhesterol. It greatly increases your risk of heart disease, so much so that the FDA (Food and Drug Administration) has prohibited food manufacturers from adding the major component of trans fat to foods and beverages. It can be found in foods like:
- Fried food (fries, donuts etc..)
- Baked goods (cakes, pies, cookies)
- Margarine
- Frozen pizza
- Microwave popcorn
Saturated Fat: Now deemed not as bad as first thought. Not as good as the unsaturated group and again solid at room temperature. Most saturated fat is animal fats. Found in fatty meats or dairy products:
- Fatty beef, lamb or pork
- Whole milk
- Butter
- Cheese
- Sour cream
- Tropical oils (coconut oil, palm oil)
Monounsaturated Fat: One of the healthy fats. It is liquid at room temperature but will start to harden when in the refrigerator. Can do the opposite of trans fat by helping to reduce the ‘bad’ colhesterol and help develop and maintain cells. Found in plant foods:
- Nuts
- Avocados
- Vegetable oils
Polyunsaturated Fat: The other healthy fat. Polyunsaturated fats include omega-3 and omega-6 fats. Known as essential fats because our bodies can’t make them and are needed for brain function and cell growth. We are only able to get them from food. Mainly found in plant based foods and oils:
- Fish
- Vegetable oils
- Nuts
- Seeds
Omega-3 fatty acids are good for our hearts. They help:
- Reduce triglycerides, a type of fat in your blood
- Reduce the risk of developing an irregular heartbeat (arrhythmia)
- Help prevent the clogging of arteries
Omega-6 fatty acids help:
- Control blood sugar levels
- Reduce risk of diabetes
- Lower blood pressure
Carbohydrates
When trying to lose weight or body fat, carbohydrates get a bad name, however, they are essential to keep us going throughout the day. There are three main types of carbohydrates: Sugar, starch and fibre. When we eat carbohydrates ‘carbs’, our body has to break them down into single sugar units called Glucose. This is what the body needs. If we don’t have enough the body becomes tired and fatigued.
Carbs can also be broken down into Simple and Complex.
Simple carbs are broken down and processed quickly into glucose and give us a quick boost of energy. 
Sugar falls into the the simple carbs category. Often associated with sugary drinks or chocolate bars, they can also be found in milk and fruit which will give us other nutrients we actually need. Simple carbs by themselves in limited quantity are not bad for us. It’s when it is added to processed food in the form of sucrose (table sugar), high fructose corn syrup or agave syrup they are bad and have all be proven to have detrimental effects on our health if taken too often or too much.
Why do they cause us to put on weight? Because they are very high in calories and do not fill us up. (They promote the hormone Ghrelin which controls hunger, making us want to eat more.) When consumed regularly or in high amounts they cause our blood sugar levels to rise. If this happens frequently there is too much sugar in the blood and we get hyperglycaemic which can not only cause harm to your body, but affect insulin resistance which affects weight gain.
Simple carbs in the form of glucose will be taken by athletes before, during and after exercise. And in small doses in the correct form these are not bad for us and will improve our endurance and performance.
Some examples of simple carbs are:
- Sugary drinks
- Baked desserts
- Sweets
- Sugary breakfast cereals
- Fruit juice concentrate
- Chips
Complex carbs are harder to break down, take more time and give us a slower release of energy.
This makes them more filling and therefore better for weight control. Fibre and Starch fall into this category. They are generally the better form of carbohydrates but, occasionally, are also found in food with little nutritional value, like refined white flour.
Fiber is found in plant based foods, like fruits, vegetables and grains. However it is unable to be broken down and digested by the body so it acts like a natural scrub. It helps other food and waste products move through our gut and carry’s a lot of bad stuff out with it.
Starch is another important form of energy. Starch and fibre often overlap and some food contain both. It also gets broken down into glucose. Starchy foods provide important nutrients, including B vitamins, calcium and iron.
Fibre and Starch are both good for our digestive health and can help prevent heart disease, strokes and type 2 diabetes.
Examples of foods containing fibre:
- Vegetables
- Fruit
- Nuts
- Grains
- Brown rice
- Beans
Example of foods containing starch:
- Potatoes
- Breads (wholemeal, granary, seeded)
- Pasta
- Cereal products
- Rice and grains
Protein
Protein is the best macronutrient for controlling weight and fat loss. It increases metabolism and significantly reduces appetite. 
It is proven to be the most filling macronutrient. If you increase your protein intake throughout the day you’ll automatically start eating fewer calories, leading to weight loss and fat loss.
Protein isn’t just used for managing weight. It is an essential part of a healthy diet.
- Protein is made up of amino acids and your body needs these to build and repair muscles and bones and to make hormones and enzymes.
- It is also broken down as energy and carries oxygen, in the blood, around the body.
- It helps make antibodies that fight off infections and illnesses and helps keep cells healthy and create new ones.
Protein, also, isn’t just found in meat, some of the highest sources of protein are plant based.
Foods containing protein:
- Meats (like chicken, beef, turkey, pork, duck)
- Seafood (like salmon, tuna, cod, herring)
- Plant based (Tofu, soy, quinoa, edamame, oats, barley, nuts)
- Dairy products (Eggs, milk, cheese, yoghurt)
Thermic Effect of food (TEF)
As we digest food after eating, our metabolism goes up slightly as the body tries to process this food. We basically burn calories to digest that food. The thermic effect of food (TEF) is the energy required for this digestion, absorption, and disposal of nutrients. Different foods will give different energy expenditure. For example, protein contains 4 calories per gram. However most of these calories are lost as heat when the body metabolises the protein. Looking at other food groups we can see the approximate amount of energy required to burn them:
- Fat: 2-5%
- Carbohydrates: 5-10%
- Protein: 20-30%
From these numbers we can see that the body will use a lot more energy to try and process protein. For example, if we had 200 calories of protein (using TEF of 25%) we would end up with 150 calories. And if we had 200 calories of fat (using TEF of 3%) we would end up with 194 calories. The body would have used the other calories to absorb and digest the food. In this way it has been proven that high protein diets can burn as much as an extra 100 calories a day.
You may have also heard that there are certain foods with ‘negative calories’. This is based on the this Thermic Effect. It implies that you burn more calories eating and digesting that food than the food contains. Whereas tests have not proven this theory, foods containing high water and fibre content, like celery and cucumber have been said to be part of this group.
Sugars
There are two main types of sugar in your diet. Glucose and Fructose. They both give the same number of calories gram for gram but they are processed differently by the body. Glucose can be metabolised by all the body’s tissues whereas, fructose can only be metabolised by the liver.
Glucose is, generally, the better sugar for you as fructose does not stimulate the satiety centers (area concerned with food intake) in your brain in the same way as glucose, leading to feeling less full. Fructose has been linked with the hunger hormone, Ghrelin, making you feel more hungry and also has been shown to increase abdominal fat significantly, affect colhesterol and insulin resistance.
It should be noted though that this is only if taken in excess, fruits contain fructose but we wouldn’t want to cut them out of our diet. They provide an valuable source of nutrients which offset the amount of fructose.
The Glycemic Index
This is the measure of how quickly blood sugar levels rise. It is measured on a scale of 0 to 100
Simple or refined carbs are broken down and absorbed by the body very quickly, leading to a spike in blood sugar levels. However when this happens quickly it also leads to a crash an hour or two later, giving cravings for another high. So we end up heading off to get another high carb snack. This can lead to a blood sugar rollercoaster and significant overeating.
The Glycemin Index (GI) of foods lets you see how quickly, or slowly, the food is absorbed into your system. Food with lower numbers helps to keep blood sugar levels more constant and results in longer lasting satiety (feeling of fullness). A guideline for the index is:
Low = 55 or less
Medium = 56 – 59
High = 59 or higher
A few examples:
Glucose – 103
White bread – 79
Bolied potato – 78
Wholemeal bread – 74
Sucrose – 65
Honey – 61
Potato chips – 56
Rolled porridge oats – 55
Ice cream -51
Spaghetti – 49
Chocolate – 40
Carrots – 39
Milk – 38
Kidney Beans -24
Fructose – 15
For a fuller list, try Harvard Health or a complete list with detailed break down University of Sydney GI Research
Summary
Even though a calorie is still a calorie there are a lot more things to consider. The vital nutrients we get from food, not only from calories, are just as important because all foods affect our bodies, in both good ways and bad. For fat loss or weight loss, a calorie deficit is required. How you get those calories is of vital importance to your body’s overall wellbeing and knowing which foods, will help you achieve your goal, like choosing ones that will help keep the hunger cravings away, or are simply just low in calories or maybe provide other nourishment.
As usual please feel free to leave comments or questions below
