Dont Fear the fat
New reports from the national obesity forum have shunned the major public health bodies who encourage a diet of low fat and low calories products.
Major health bodies which include the Government, regularly promote a balanced diet based on the ‘eat well plate’ model. This model is a broad format of what they recommend people should be eating on a regular basis.
At present the eat well plate model dedicates almost two thirds of the daily diet to refined foods such as pastas and rice, starchy carbohydrates such as bread and potatoes, and to dairy, sugary and treats. The other third is dedicated to fresh fruit and vegetables, meat and fish.
This contradicts the recent research that has proved that a diet that is high in starchy carbohydrates, which are a type of sugar and refined foods such as breads and pasta, can make blood sugar levels (glucose) peak.
Why we need glucose
Our bodies have glucose in the blood because our brain uses it for energy to work. As well as the brain our organs and cells also use the energy provided by glucose – so it is a vital component to fuelling the body. The brain can only use glucose, so our bodies convert other sugars into glucose – so for example a baby will convert the lactose in its mother’s milk into glucose to give it the energy to grow.
Our glucose level is controlled by the hormone insulin. When glucose levels are too high insulin is released from the pancreas to remove glucose and regulate blood sugar.
If glucose levels in blood get too low then glucagon, cortisol and adrenaline are released to increase it again. When we need energy these processes make our bodies release any stored glucose (glycogen) back into our blood.
But insulin also has other functions. One of them is sending signals to our fat cells. Insulin tells the fat cells to pick up fat from the bloodstream and store it when there is enough energy already present with blood sugars. So, when insulin levels are chronically elevated (i.e. prolonged high blood sugar levels), much of the energy in our bloodstream gets selectively deposited in the fat cells and stored.
What is GI?
The glycaemic index (GI) is a measure of how quickly blood sugar levels rise after eating a certain food. Glucose has a benchmark index of 100.
The GI estimates how much each gram of available carbohydrate (total carbohydrate minus fibre) in a food raises a person’s blood glucose level following consumption of the food, relative to consumption of pure glucose.
So those foods that tend to break down quickly during digestion and release glucose into the body at a fast rate have a high GI and foods that breakdown slowly and release glucose on a slower scale have a low GI.
- High GI = Fast release of glucose
- Low GI = Slower release of glucose
Confectionary, white bread, white pasta, most white rice, cornflakes, potatoes, parsnips and bagels are all foods with a high GI.
Diets rich in carbohydrates with a high GI can secretly grow fat and increase waist lines.
1984 saw the launch of a massive campaign to promote low fat diets in the battle against heart disease – we were told to eat less fat and we did. Saturate fat consumption declined. But our waste lines did not and obesity and diabetes were on the increase.
As a result of removing high fats from diets, more carbohydrates in the form of high GI foods, such as the aforementioned pastas, breads and rice were consumed.
Stanford University put two diets to the test- one high in fat and protein but low in carbohydrates and one high in carbohydrates but low in fat. The results were those that limited their carbohydrate intake but ate as much fat and protein as they liked, lost more weight on average than those who ate a diet rich in carbohydrates and low in fat. These results suggest that fat doesn’t make you gain weight, but carbohydrates do. But how is that so?
Here comes the science
Fat is always flowing in and out of our cells but that fat that is stored in our cells is what makes us over weight
Fat is stored in the form of Triglycerides. Triglycerides are 3 fatty acids bound together by one molecule of glycerol inside a fat cell. This one molecule is too large to flow through the membranes of a fat cell, so unless the Triglycerides molecule is broken down, the fat is not going anywhere!
What makes us fat?
The flow of fatty acids into fat cells.
Insulin is released when we eat and those foods that are GI high – such as carbohydrates encourage the release of lipoprotein lipase (LPL) which pulls the fat into the cell.
The most easily digestible carbohydrates make us fat because they pump glucose into the blood stream quickly to produce insulin levels to spike.
So when insulin levels go up – we store fat.
Carbohydrates boost insulin and insulin boosts fat storage.
What makes us lean?
Anything that breaks down those triglycerides.
The new report is an attempt to encourage people to start thinking about good fats that come from foods such as Avocados, oils such as coconut and olive, nuts and eggs. These types of fats are not as harmful to our bodies because our bodies know how to deal with them.
Unsaturated fats contain a higher proportion of unsaturated fatty acids and are usually liquid at room temperature. Monounsaturated and polyunsaturated fats help to maintain healthy cholesterol levels and are found in vegetable oils such as olive, rapeseed and sunflower oils, avocados, nuts and seeds. Polyunsaturated fats provide us with essential fatty acids like omega-3 which are important for health.
Omega 3 fatty acids
These are a group of polyunsaturated fatty acids. These are found in oily fish (e.g. mackerel, salmon and sardines) and in smaller amounts in sunflower oil, flax, linseed oil and walnuts. Omega 3 fatty acids are associated with good heart health as they can help to prevent blood clotting and regulate heart rhythm. They are also important during pregnancy and breastfeeding to support child development. In order to get the benefits from these fatty acids we should all aim to eat at least one portion of oily fish per week.
- Good sources include mackerel, salmon, pilchards, sardines, kippers, herring, trout, fresh crab, whitebait and swordfish
Why is fat easier to burn than carbohydrates?
One word; Ketosis. Ketosis is the state that your body enters into when it starts converting stored fat into ketones to use as fuel for your cells. If you eat plenty of carbohydrates, you will never enter into ketosis. Instead, your body will simply use all that glucose as a fuel.
Path to a happy diet
The advice in line with the recent report from the National Obesity forum is that a diet high in carbohydrates is associated with increased weight gain because our bodies store the carbohydrates as fat.
Conversely by eating a diet rich in natural fats such as avocados, nuts, meats high in omega 3 and 6, fish, and some dairy, our body will actually be able to convert that fat to burn immediately rather than storing it.
Before the invention of processed foods we only had access to meats, vegetables, fish, nuts and seeds and some dairy. This diet today is known as the Paleo way and is becoming increasing popular as a natural way to live.
Evolution & diet
It is not surprising that our bodies react adversely to breads, cereals, pastas and rice and other carbohydrates in the form of processed foods, sweets and chocolate. In the natural world there are fewer sources of concentrated carbohydrate – some starchy pulses and roots, but generally speaking it requires agriculture and farming to allow us to gather enough carbohydrate base foodstuffs to make for a viable source of food.
Our ancestors were hunter-gatherers, and our bodies have been evolving for hundreds of thousands of years on a low GI omnivorous diet on which they lived. Agriculture and the cultivation of crops is probably only 10,000 – 12,000 years old, so the human body has spent most of its existence solving dietary needs of hunter-gathering, not an agrarian diet. So to give your body what it needs, it helps to provide a diet that is more in line with what it has evolved to do – low GI, high-fibre and varied (with less carbohydrates).
The key to a happy and healthy relationship with food is to eat a wide and varied diet. Too much of one type of food will not be good for your body. In the same way that eating too many foods rich in carbohydrates will be detrimental to your health, eating too many foods high in fat will also have adverse effects on your body.
According to the report from the National Obesity forum, the shift from a diet high in carbohydrates to a diet higher in good healthy fats needs to happen to help tackle the diabetes and obesity crisis in the UK.