Understanding the food

Food sustains us, promotes growth and provides our body with the fuel to make energy.

We need three types of nutrients to maintain a healthy body. These macronutrients are carbohydrates, proteins and lipids (fats) and can be used by the body in different ways. Almost all food contains some carbohydrate, protein and fat, but certain foods may be higher in one of these nutrients than others. For example, pasta is highest in carbohydrates so we consider pasta to be a carbohydrate food.

Each of the three macronutrients has an amount of energy the body can either use immediately or store for later use:

1 gram of carbohydrate has 16 kj (4 calories)
1 gram of protein has 17 kj (4 calories)
1 gram of fat has 39 kj (9 calories)

The more kilojoules (calories) in a particular food, the more fuel it creates to run the body. Of course, the problem is that many of us eat more kilojoules (calories) than our body needs on a daily basis, and eventually these extra kilojoules (calories) end up being stored as fat.


Carbohydrates are an important macronutrient, and should provide about 50% of your daily calorie quota. Carbohydrates are mostly used for providing energy to run your body. Functions such as brain functions and muscle contractions mainly use energy derived from carbohydrates. The quality
of a carbohydrate food can be defined on the basis of its glycemic index (GI). The glycemic index is a rating system that compares foods in terms of how they affect blood sugar levels. Low GI carbohydrates release energy into the body at a slower rate than high GI foods. The slower release of energy means you sustain energy levels for longer and also feel fuller for longer. The Kate Morgan maintenance program focuses carbohydrate intake on low GI carbohydrates. You should develop a preference for low GI carbohydrates over high GI carbohydrates as you develop your new eating pattern. Low GI foods are foods with a GI less than 55. They cause a slower and lower rise in blood glucose levels. Intermediate GI foods are foods with a GI between 55 and 70. They cause blood glucose levels to go up at a moderate rate. High GI foods are foods with a GI greater than 70. They cause a rapid rise in blood glucose levels. The following table is an extract from “Diabetes Australia” website. It shows the GI rating of some common foods.

Low GI

Intermediate GI

High GI


Burgen Soy-Lin PerforMAX® fruit loaf, Vogel’s honey and oat®


Hamburger bun, rye bread, croissant, light rye, crumpet, wholemeal


White bread, bagel, blackbread, wonderwhite®, gluten free bread

Breakfast Cereals

All Bran fruit'n oats, All Bran® Gruadian® porridge, Special K® Riece Bran

Breakfast Cereals

Oatbran, untoasted muesli, Just Right® Nutri Grain® Sustain® Weet-Bix®

Breakfast CerealsSultana Bran® Bran Flakes® Coco Pops® Puffed Wheat® Rice Bubbles® Cornflakes®


Barley, Pasta (all types), Noodles, Bulgur, Semolina


Basmat rice, wild rice, Sunrice Doogara® rice, Mahatma Premium® Classic, Couscous, cornmeal, tapioca


Brown rice, calrose rice, jasmine rice


All Beans (Kidney, soy, baked bean, etc...) peas, and lentils



Broad beans

Starchy Vegetables

Sweet potato, taro

Starchy Vegetables

New potato

Starchy Vegetables

Other potatoes, parsnip, french fries

Dairy Foods

Milk, So Good® soy drink, low fat fruit yoghurt, custard, low fat ice cream

Dairy Foods

Full cream ice cream





Digestive, Shedded Wheatmeal, Milk Arrowroot


Morning Coffee


Cherries, grapefruit, peach, dried apricots, apple, pear, plums, orange, grapes, kiwi fruit, banana


Sultanas, raw and canned apricots, mango, paw paw, raisins, rockmelon, pineapple





Protein is needed to help build and repair the body and muscles and to make a range of enzymes and hormones. Proteins are made up of amino acids of which there are 20 essential to our health.

Think of amino acids as building blocks the body can arrange in thousands of different ways to make all the specialized proteins it needs. Our body can make 11 of these amino acids. The remaining 9 amino acids must come from food sources (these are called essential amino acids).

Protein that comes from animal sources is called complete protein as it contains 9 essential amino acids. Plant foods do contain protein, but are called incomplete protein foods because they don’t have enough of the 9 essential amino acids (with the exception of soy protein which contains complete protein). Interestingly, eating 2 or more types of plant foods together can make complete protein.

Example of protein food are:

  • Meat, including beef, lamb and poultry
  • Fish, including shellfish
  • Eggs and dairy foods such as cheese and milk
  • Peanuts
  • Kidney beans
  • Some foods can be high in both protein and fat: examples of these are nuts and cheese.


Lipids (fats and oils) have twice the energy per gram of either carbohydrates or proteins.

There are two kinds of fats available in food; saturated and unsaturated. Saturated fats are commonly derived from dairy and animal products and unsaturated fats are found in vegetable oils. Most fats contain a mixture of both. Go another step and you can distinguish unsaturated fats between polyunsaturated and monounsaturated.

Saturated fats, when eaten in excess increase blood cholesterol levels, while unsaturated fats, particularly monounsaturated fats like that found in olive and canola oil are recommended to help maintain healthy cholesterol levels. People eating an olive oil rich Mediterranean
diet have low rates of heart disease.

Polyunsaturated fatty acids found in fish are called omega-3s and are known to support heart health, joint mobility, balanced mood and mental function and may help protect against a whole range of other illnesses.

Healthy fats

Unhealthy fats

  • Poly and mono unsaturated spreads and oils (canola, sunflower, olive)
  • Fish such as salmon, herring, mackeral
  • Avaocados
  • Nuts
  • Baked products such as cakes, biscuits, pastries, some margarine
  • Fast foods such as pies, pizza, hamburgers
  • Fatty processed meats


We also need very small quantities of micronutrients from food for our bodies to function. Micronutrients include vitamins and minerals such as folate, iron, zinc and iodine. Vitamins and minerals don’t contain any kilojoules.

There are 13 different vitamins, each with its own specialised job such as helping release energy from food, blood clotting, cell division and vision. Minerals are found in the fluids of the body and also form much of the structure of the body such as bones and teeth.


Understanding your body

Your body absorbs the goodness from what you eat through the process of digestion.

The human digestive system can be thought of as one continuous tube about 7 to 8 metres long that consists of the mouth, the throat, the oesophagus, the stomach, the small intestine, the large intestine and finally the rectum. Each part of the digestive system has a specialised role, and as a whole is very well designed to digest, absorb and eliminate the foods and fluids we take in each day.


Digestion begins in the mouth by chewing the food into smaller pieces and mixing it with saliva to help with the dissolving and swallowing of food. Enzymes produced in the mouth start the process of carbohydrate digestion by helping to break down starch into simple sugars.


Once food is swallowed it is carried down the oesophagus to the stomach where it is churned by movement of the stomach walls to ensure it’s mixed with acidic digestive juices. At this stage the food is a creamy mixture called chyme.

The stomach helps to further break down food, especially the protein component, over a period of between 1 and 4 hours until the chyme leaves the stomach and goes into the small intestine.

Did you know?

The acid in the stomach is so strong it kills most bacteria and is similar to acids used in industrial metal cleaners.

Small intestine

The small intestine is where most of the nutrient-digesting activity happens. It is here that the chyme is mixed with acid- neutralising fluids secreted by the pancreas. The pancreas also secretes juices containing different enzymes that act together on food to further break down carbohydrates, protein and fat.

The pancreas is responsible for producing insulin, the key hormone that allows the body to utilise and store nutrients. Meanwhile the gall bladder secretes bile (made by the liver) into the small intestine to aid the digestion of fat by a process called emulsification. Once the food is reduced to small particles most of it is absorbed through the walls of the small intestine and the nutrients are carried into the bloodstream.

Large intestine

Any nutrients that can’t be digested (including fibre) pass into the large intestine. The large intestine begins at the colon where some of the remaining nutrients can be absorbed. After this point anything left is waste for elimination.

The large intestine is wider but shorter than the small intestine. About 1.5 metres in length, its primary function is to absorb water and electrolytes that already passed unabsorbed through the small intestine.

How does the body make energy?

The majority of what we eat each day has one main purpose; to provide energy for the body to carry out its many complex functions. The energy in food comes from the chemical bonds between the atoms in carbohydrate, protein, fat and even alcohol. Each of these nutrients can be metabolised or broken down into simpler molecules through different biochemical pathways to make energy. Every cell in your body needs to make energy from nutrients to function.

The main energy currency of all cells in the body is called ATP (adenosine triphosphate). For a typical adult eating a normal diet, almost all the ATP they make in their cells each day comes from the carbohydrate and fat they eat; only small amounts of ATP comefrom protein.

When less food is being eaten fat stores are increasingly relied upon to make ATP and that’s why people lose body fat when they reduce their intake.

The body is continually breaking down ATP every second of the day so much of the energy in food goes towards helping the body to remake ATP.

While the body can make some ATP from glucose without needing oxygen, almost all of the ATP made each day comes from metabolic pathways that require oxygen. This is called aerobic metabolism.

When we increase the intensity of exercise our breathing rate noticeably increases as the body needs more oxygen to ‘burn’ fuel, in this case a combination of carbohydrate and fat to meet the energy needs of contracting muscle. Just like a fire needs oxygen to burn wood, the principle applies in the making of energy from food.

Many parts of the body including the brain, nervous system and contracting muscle prefer to use glucose (carbohydrate) to make ATP rather than fat. In times of fasting or on a low- carbohydrate diet, the body cannot make enough glucoseinternally for its needs so the brain and the nervous system turn to an alternative fuel source – ketone bodies made from fat by the liver - to meet the shortfall.

The term ‘ketosis’ describes high levels of ketone bodies in a person’s blood. It doesn’t slow or speed the effectiveness of the diet. It’s simply symptomatic of low levels of carbohydrates in the body.

An amazing fact:

The continual breaking down and resynthesising of ATP means each person makes their own body weight in ATP every day!

What is energy used for?

Even when resting the body uses a large amount of the energy it makes just to maintain and support itself. The term for this essential energy is the Basal Metabolic Rate (BMR).

For an average adult BMR can account for up to almost 70 percent of their daily energy needs. BMR is affected by many things

Factors affecting BMR

  • Amount of muscle
  • Gender (males tend to have a higher BMR than females because of more muscle)
  • Age (BMR decreases 2% per decade with age)
  • Genetics (inherited tendency to certain conditions that affect metabolism)
  • Thyroid hormone levels (an under active thyroid gland dramatically reduces BMR)
  • Pregnancy and rapid growth (eg; growth spurts, healing after illness or injury)
  • Illness and stress (increases metabolism) Weight loss (lower BMR)

For most people physical activity accounts for just 20 to 30 percent of the body’s total energy output each day. The amount of energy (kilojoules) used for an activity depends on the intensity level and duration of the activity which is why sportspeople can have energy needs from physical activity much greater than their BMR.

Activity level


Kilojoules (calories) per hour

Resting Sleeping, lying quietly 357 (85)
Very light Watching TV, eating 445 (106)
Light Household chores 827 (197)
Moderate Walking, easy cycling 1255 (299)
Heavy Swimming, running, basketball 2625 (625)


There is a myth that weight gain is caused by a ‘slow metabolism’. In fact BMR usually increases rather than decreases as people gain more weight because the more you weigh the more energy needed to maintain your body because there if more of you to support. Only in rare situations where a person may have an underlying medical condition such as an under active thyroid gland could weight gain be due to ‘slow metabolism’.

While adults’ energy levels can be divided between BMR and physical activity the bodies of growing children, adolescents and teenagers also use energy to produce new body tissue such as bone, muscle and blood so they can have higher energy needs per unit of body
weight than adults.

How does the body make fat?

Fat, or adipose tissue, is generally found underneath the skin (subcutaneous fat).

The main job of the fat cells making up this adipose tissue is to store fat. Fat cells have an incredible capacity to store fat with a ‘full’ cell containing almost 99 percent of its weight as fat. When people talk about weight gain they’re usually referring to an increase in body fat. Overeating results in increased fat storage as the body has more energy than it needs so it stores the excess nutrients (usually dietary fat) in fat cells where it can be called upon in times of food scarcity such as dieting.

As a person gains weight and the fat cells fill and expand, the cells can eventually multiply to allow more fat storage. There appears no limit to how much fat humans can store.

Why does the body store fat?

Our body is designed to ensure survival. As humans evolved, the ability to store fat was essential as a means to survive food shortages because the stored fat could be used by the body as an emergency supply of energy.

Our bodies haven’t changed much over time, but the way we live has. We are still genetically designed to store fat even though food shortages in Western societies are rare.

We eat more today and more often than our ancestors
did and we don’t have the opportunities to burn off the excess energy. Our bodies don’t know there isn’t a famine around the corner and store that energy as fat just in case.

Everyone is different and there are a variety of reasons more and more of us are finding the management of our weight a challenge.

Certainly environmental factors play a major role. There is a predominance of processed and fast food, the seemingly easy option when our lives are so busy.

Many people are ‘emotional eaters’ and overeat during times of stress or trauma.

There are also genetic reasons (eg; an inherited medical condition meaning we could be overweight regardless of other factors).

The health consequences of carrying too much weight

Overweight or obese people are more likely to develop a number of debilitating or life threatening conditions including:

  • Type 2 diabetes
  • Heart diseases
  • Stroke
  • High cholesterol
  • High blood pressure (hypertension)
  • Gallbladder disease
  • Infertility
  • Osteoarthritis
  • Sleep apnoea and respiratory problems
  • Some cancers (breast, colon, endometrium and oesophagus)


Excess weight makes it more difficult to take part in regular exercise which can create a vicious cycle making it not only harder to lose the weight, but also further increasing the risk of some diseases where exercise is known to be beneficial.

The more overweight a person is, the more likely they are to have health problems.

Studies have shown that even losing a small amount of weight, say 5 to 10 percent, combined with exercise can improve health and help reduce the chances of developing serious health problems.

How is body fat reduced?

When we eat much less than we normally would (such as during illness or when under a lot of stress) the body still needs to meet its energy requirements.

As a person loses weight they lose a combination of water, carbohydrate (stored glycogen) and protein but it’s the bodies fat stores that are most depleted. To use stored fat, special enzymes help liberate the fatty acids stored in a fat cell so they can be oxidised to make energy (ATP). As more fat is used the amount of fat stored within each fat cell decreases and the fat cell simply shrinks in volume. This is how the Kate Morgan Weight Management Program works.

While it may seem that eating as little as possible is a good way to lose the most weight, research has shown that reducing energy intake too much causes the body to burn more protein from muscles in order to supply energy and essential amino acids (if very little protein is eaten in the diet) and this can severely lower the metabolic rate, making it more difficult to lose weight.

Reducing kilojoules on a gradual and steady basis helps limit a decrease in metabolism and loss of body protein and ensures you are still eating enough food to provide the body with essential proteins, vitamins and minerals for good health.

The Kate Morgan meal replacements are designed to speed up the process of fat burning while ensuring that the body retains its essential proteins, vitamins and minerals.

Is exercise necessary for weight management?

As a person loses excess weight, even when they are eating well, they will be losing both fat and muscle. Being active helps the body lose more fat than muscle as it preserves the muscle out of necessity.

Having more muscle helps burn more energy during the day, further helping the process. Muscle tissue, unlike fat, is metabolically active. Muscle burns kilojoules even when it isn’t being used. A person with a high proportion of muscle will burn more kilojoules over the course of a day than someone of the same weight with less muscle.

The spot reducing myth

There is no ‘magic’ diet or exercise that can target the removal of fat from certain body areas. Fat loss follows the principle of ‘first on, last off’ meaning the first place you store fat when you gain weight will be the last place you lose it. With regular exercise and correct dietary changes you’ll decrease overall body fat and this will also help reduce fat in the most abundant parts of the body or those problem areas.