What makes us fat?
A simple look into the basic principles of fat gain.
Firstly what is fat?
Fat, referred to as adipose tissue or adipocytes for the individual cell (adipo =fat cyte=cell), is stored energy with a single pound of fat containing roughly 3,500 calories of stored energy.
The human body stores energy in three different ways:
- As glycogen in the liver and muscles
- As fat in adipose tissue
- As amino acids in muscles
Fat is stored as adipose tissue in almost every region of the body and is the most efficient energy storage. A very small amount is stored in the muscles (intramuscular fat, although obese people will have larger amounts of this than others), however the majority of our fat is stored around the organs (visceral) and beneath the skin (subcutaneous). The amount stored in different parts of the body depends on genetic make-up and individual hormone balance.
Fat distribution from hormone balance is often noted in the difference between fat storage for men and women. For men fat storage is usually around the middle giving them an ‘apple’ shape whereas women often hold more fat around the hips and thighs making them more ‘pear’ shaped.
Fat whilst being an amazing energy source has other roles, such as insulation and protection of vital organs as well as playing a role in immune and inflammatory responses. Fat cells have also been shown to play roles in overall glucose metabolism, blood pressure, appetite, fuel utilization and hormone production.
So what makes us Fat?
One of the main causes of gaining weight (fat) is through refined carbohydrates.
Refined carbohydrates cause a swift and excessive rise in blood sugar levels, this triggers the body to release the hormone insulin to drive the sugar out of the blood and into cells. However insulin also causes the body to promote fat storage and encourages fat cells to swell. It is a common myth that you don’t make new fat cells, you are born with a certain number off fat cells and you may develop more during puberty but that’s it. This is incorrect, as fat cells swell and reach tipping point they multiply via a process called mitosis. Insulin spikes, that cause the fat cells to swell can encourage your fat cells to multiply as well.
As more fat is packed into the body it interferes with insulin efficiency and glucose uptake in your muscles and organs. Your pancreas will then release more insulin as blood glucose levels remain high. This higher insulin level encourages an efficient conversion of your caloric intake into body fat.
Excess insulin is then followed by a sugar crash at which point sugar cravings kick in, increasing your appetite in a cycle that will lead to obesity.
Excess body fat accumulated causes a decrease in insulin efficiency in the cells leading to insulin resistance. Insulin resistance causes higher insulin spikes and more fat storage… you can see it’s a cycle you don’t want to get into.
But what about eating fat?
Fat is actually more likely to make you fat than any other nutrient as it is stored as adipose tissue if it is not needed straight away.
The body converts food fat into body fat quickly and easily. 100 calories of ingested fat can be converted to 97 calories of body fat by burning only 3 calories.
However this is not to say eating fat will make you fat, if your calorie consumption is under your total daily energy expenditure your body should use the fat rather than store it. It is only to say when carbs, fats and proteins are consumed, the fat consumption is more likely to be stored as fat as glucose and protein are used more efficiently by the body or tend to be stored as glycogen in the liver and muscles or amino acids in the muscles.
Carbohydrates and proteins produce a rise in blood glucose which usually helps reduce the appetite, fat on the other hand is more easily absorbed and often actually depresses blood glucose, thereby failing to satisfy the appetite sufficiently.
Fat is also more calorie dense and usually provides less bulk so people tend to overeat fat more often than other nutrient groups.
So what does all this mean?
To Summise, Fat is predominantly an energy store in your body. The food you eat constitutes an energy source, if we take in more energy than we burn then we will store the rest of the energy for another time.
Excess eating is what leads to fat gain. However .....
This process is worsened when refined carbohydrates are eaten causing insulin spikes and non-essential fats are eaten which are more easily absorbed into the body, when these two things are eaten together you have a recipe for obesity so avoid processed food high in both.
“Not all calories are created equal” Our internal processes largely determine the amount and speed of the body fat storage. To loose weight food choice is just as important as the total calories in them.