Two out of every 3 adults in Australia are overweight or obese, which means almost 70% of adults in this country are carrying excess body fat. For kids, they do a little better, but better is a morbid word in this context. Statistics from 2014 showed that 1 in 4 (25%) children are overweight or obese, and fearfully, this number is climbing.
Carrying excess body fat is the number one risk factor for type 2 diabetes, with studies showing that ~90% of those who develop the disease are overweight.
DIETARY FATS & INTRA-MYO-CELLULAR LIPIDS
When an excess of dietary fats are consumed, fat cells in the body can get so overfilled that they actually start spewing fat back out into the bloodstream, resulting in elevated blood lipid levels. This excess blood fat can end up in muscle cells, build up, and create toxic breakdown products and free radicals. The build up of fat in muscle cells is referred to as “intramyocellular lipid” excess.
Intramyocellular lipids affect the insulin signalling process, which is the process that allows glucose to move from the blood into your muscle cells. The more fat that builds up in muscle cells, the more resistance there can be on normal insulin signalling. Eventually this can result in a condition called “insulin resistance”.
Insulin resistance is the major cause of type 2 diabetes.
In short, your blood contains glucose that needs to get from your circulation into your muscle cells, where it can be turned into energy (ATP). For the glucose to get in, insulin is required to open up doors located on your muscle cells; this then allows glucose to glide right into the cell. Insulin basically acts like a key to open up doors on your cells.
An excess of intramyocellular lipids (fat in your muscle cells) can gum up the locks on muscle cell doors, resulting in insulin not being able to open the cell doors effectively. The body then tries to compensate by making more and more insulin. But the insulin just can't do its job properly due to the insulin resistance (gummy doors). Consequently, because glucose can’t get into the cells efficiently, it stays in the blood for longer, builds up (aka. high blood glucose levels) and reaps all sorts of damage to the bodies small blood vessels.
Hence, carrying excess body fat (overweight and obesity) and consuming excess dietary fat, can lead to insulin resistance and in turn cause type 2 diabetes.
Fortunately, research shows that you can lower your insulin resistance via decreasing the amount of fat in your diet.
NOT ALL FAT IS BAD FAT
Whenever you eat food you will consume carbohydrates, proteins and/or fats. Fats come in varying forms, including monounsaturated, polyunsaturated and saturated. Monounsaturated fats, found in avocados, nuts and olives, and polyunsaturated fats, found in flaxseeds, chia seeds and walnuts, deliver a number of health benefits when consumed, including: improving blood cholesterol levels, reducing inflammation and reducing insulin resistance. On the other hand, saturated fats, found in animal foods (e.g. meat and dairy), can increase cholesterol levels, increase inflammation and increase insulin resistance. Palmitate for example, is one particular type of saturated fat that has been shown to cause insulin resistance.
When saturated fats (SF) build up in muscle cells they can cause both toxic breakdown-products and free radicals to accumulate. This results in increased inflammation, mitochondrial dysfunction and impaired insulin signalling.
Saturated fats are strongly linked to high blood cholesterol levels, inflammation, insulin resistance and type 2 diabetes.
The Heart Foundation of Australia, Diabetes Australia and The Nutrient Reference Values for Australia and New Zealand, recommend limiting your SF intake to less than 10% of your total daily calorie intake (best practise is less than 7%). This means that the average (healthy weight) person who consumes about 2000 calories per day should aim to get less than 200 calories from SF. This equates to about 20 grams or less of SF per day.
The major sources of SF in an average Australian’s diet:
Full fat milk, butter and dairy products
Meats (sausage, bacon, beef, lamb, burgers)
Biscuits and pastries
EXAMPLE - A DAY ON A PLATE
An average day on a plate for an average Australian can include:
BREAKFAST// 2 slice toast with butter (8g SF) + vegemite or 1 cup cereal with 1 cup full cream milk (5.6g SF) MORNING TEA// Large flat white coffee (8g SF) and a sweet biscuit (2g SF)
LUNCH// Chicken (1.5g SF) and salad sandwich with cheese (6g SF)
AFTERNOON TEA// Fruit and yoghurt (5g SF)
DINNER// Steak (7g) and vegetables
SUPPER// Ice cream (10g SF).
This somewhat healthy looking day results in the intake of greater than 50g of SF.
FOOD SOURCES OF SATURATED FATS
MEATS, CHICKEN & FISH
Beef, steak (150-180g serve)
Beef, rissole (1)
Mince, beef (1 cup)
Mince, beef lean (1 cup)
Chicken breast, skin on (1 small breast)
Chicken breast, no skin (1 small breast)
Chicken thigh, skin on (1 small thigh)
Chicken thigh, no skin (1 small thigh)
Lamb cutlet (2 medium)
Lamb steak (1 medium)
Sausage (2 long and thing)
Bacon, shortcut (3 rashers, 22g)
Salami (3 slices)
Cows milk, full cream (1 cup, 250ml)
Cows milk, low fat (1 cup)
Cheese, cheddar (1/4 cup shredded, 30g)
Cheese, feta (30g)
Butter (1Tbs, thick spread)
Yoghurt, greek regular (3/4 cup)
Ice cream, vanilla regular (3 small scoops)
Cream (1 dollop, 23g)
Sour cream (2Tbs)
Coconut oil (1Tbs)
Coconut yoghurt (100g)
Palm oil (1Tbs)
Pizza (1 slice)
Potato chips (100g)
Corn chips (small bowl, 60g)
Hot chips (~110g, 1.5 cups)
Tim Tam biscuit (2)
Sausage roll (average)
Meat pie (average)