The Science Behind Fat Loss: Breaking The Addiction To Sweets

fat loss exercise
Jaymes Gleeson


May 15, 2024

Being swept up in addictions associated with food have deep causative roots within our psyche. The origins of these primaeval compulsions to eat sweet, high-calorie foods are so deeply embedded, and so much a part of the architecture of the mind that they’ve dissolved into the well of our belief systems, leaving us mystified as to the nature of their magnetic seduction.

To overcome the addiction to sweet high-calorie foods, an understanding of how and why their pull seems so irresistible can help break our addiction to them. So, let’s deconstruct the nature of this potent impulse down to first principles.


A first principle is a foundational proposition or assumption that stands alone: “the first basis from which a thing is known” said Aristotle. The first principle of fat loss involves an understanding that both the types and amount of calories we consume produce lipogenesis (the accumulation of body fat).

A key point, often overlooked, is that not all calories are created equal. Eating 100 calories of chocolate is not the same as eating 100 calories of broccoli. Mathematically they are the same, but nutritionally and lipogenically, they are not.

The macronutrients we ingest (carbohydrates, protein, and fat) are metabolized by the body differently, with high GI foods raising blood sugar sharply, necessitating an insulin response which stores these calories as adipose tissue (body fat).

So, for a reduction of adipose tissue to occur, there are two levels of approximation:

weight loss
  • At the first level, we must be in a negative energy balance (consuming fewer calories than we expend).
  • At the second level, avoiding foods of a high glycaemic load will remove a possible source of lipogenesis, keeping our blood sugar (and therefore insulin) levels stable. Stable blood sugar helps control high-calorie food cravings, making it easier to control overeating (removing another possible source of lipogenesis).

What lies behind these first principles? That is, what is the driver behind our intense desire to consume high glycaemic load foods, which lead both directly and indirectly to fat gain?

To understand this, we have to go back millions of years to get to the root of this evolutionary adaptation.

In this book ‘why we love sugar’, Dr Richard Johnson, explains that our earliest ancestors went through a period of significant starvation 15 million years ago. Because of this, an adaptive mutation occurred that increased these proto- humans’ sensitivities to fructose allowing even small amounts to be stored as fat. This adaptation was a survival mechanism: Eat fructose, decrease the likelihood you will starve to death. This propensity was, in turn, naturally selected in each subsequent generation.

If there is a one-word rubric through which early man’s relationship to food may be understood, it is scarcity. Our biochemistry and endocrinology has been moulded in no small way by adaptations resulting from the dearth of sweet calorie-dense food (or any food at all in many cases). These “sweet food is life” adaptations, naturally selected over the course of millions of years, became hard wired within us, and remain so to the present day.

So, here we sit in 2021, the end point of natural selection and evolution. Buried deep within our lower brain function our primordial instincts lead us, as if in a dopamine driven trance state, towards foods “it” has learned will save us from extinction.

The Real Battleground

Our prefrontal cortex (PFC) is our higher brain “executive” function. It’s what separates us from apes or proto-humans. Its highly complex processing power effectuates our ability to use self-control. It allows us the power of reasoned argument and logic for problem-solving, and to understand cause and effect, allowing for decision making and long term strategic planning. Also, it is from where traits such as morality, altruism and empathy find expression.

smile, dopamine

Dopamine is a driver towards action, and as such, it is our lower “instinctual” brain’s greatest ally. Regarding high-calorie food, dopamine is like a highly persuasive motivational speaker who provides the worst possible advice. Its priority is opposed to our long term best interest.

The two competing voices in your mind are your lower “instinctual” brain function (LBF) and your prefrontal cortex (PFC). Your internal dialogue may resemble this…

LBF: “Eat the cake! Life is for living!”
PFC: “Actions have 
consequences my friend. You want to be fat and inflamed? Think it through”

LBF: “Have another beer, hell, have another six pack!. Deal with tomorrow when it comes”
PFC: “C’mon man, put the beer down, it’s Monday night for God’s sake”

LBF: “Pastries? Absolutely! Just one couldn’t hurt, could it?”
PFC: ““What self
-respecting man eats a muffin? Get your act together, you’re embarrassing yourself”

Such mental dissension can be percolating subconsciously on an almost constant basis for those with a weight problem. You may find yourself emotionally exhausted without knowing quite why. Additionally, you may feel terrible about your own perceived weakness of will when confronting the irresistible force of sweet food.

These cravings are powerful, indeed they are quite literally a force of nature. A force that is encoded within the calculus of our genotype, finding expression in the sweet food craving, obese phenotype.

When you feel that dopamine driven excitement at the sight of a chocolate cake, or salted caramel ice cream, realise that what you are feeling is the end result of millions of years of evolution. It has shackled sweetness to survival. Your body has become chemically indoctrinated to valuing sweetness as literally a matter of life and death. As at one time it was.

Internally, our systems have not changed since our primordial origins, but externally, scarcity has become abundance, and overturned our calculus. The old rules no longer apply, but dopamine never got the memo. Sweetness no longer means survival. It can and does mean early death.

strength, mind, weight loss

An understanding of the dynamics of the battle between your lower brain primeval compulsions and your higher brain reasoned rationality can be a powerful ally in overcoming the challenge of the craving mind.

So, next time you feel the increased heart rate, butterflies in the stomach, and the generalised excitement that is the promise of sugar, remember it’s just dopamine. It’s powerful, but it’s a hormonal trick being played on you by your own chemistry. Feel its power, get your dopamine rush, but don’t act on it.

Because, ultimately we must ask ourselves “who is in charge here? Is it my higher brain function, or am I to be a perpetual victim of my animal instincts?”. That’s just embarrassing, is it not?

By acting in concordance with the evolved being I believe myself to be, I’m voting, each and every time, for the type of person I wish to become: healthy and in control of my own destiny.

The Carousel would like to thank J. A Gleeson for this article. He is a Personal Trainer at Tribe Social Fitness, Sutherland Shire, Sydney. 


By Jaymes Gleeson


J. A Gleeson is a health writer for The Carousel and Personal Trainer at Tribe Social Fitness, in the Sutherland Shire, Sydney. He has over 25 years experience as an athlete, athletics coach, consultant, personal trainer, educator and independent researcher. Jaymes won an Athletics Scholarship and studied in the United States in 1991. - San Francisco State University (Psychology, Nutrition, Athletics) - American Collage of Sports Medicine (Personal Training) Throughout the 90s he worked as athletics coach and personal trainer in the US. In the early 2000s, he worked in Snow Sports throughout Japan and returned to Australia in 2008 to continue wellness research and personal training in high end health clubs in Sydney.



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