Top 3 Weight Loss Myths: Myth Three

Diets Work

I saw a patient in my clinic last year who had been desperately trying to lose an extra 10kgs. 

She asked me 

‘How long would it take me to lose those 10 kgs if I stopped eating altogether?’

I am hoping that we are now at the point where we understand that dieting is not good for you. However, it is also important to know that it doesn’t even ‘work’ for sustained weight loss. And there are some good reasons as to why this is the case. 

To truly understand why diets fail, we need to delve into the hormonal havoc and metabolic adaptations that occur when we embark on a restrictive eating plan.

The Dieting Dilemma

While diets may offer short-term results, the majority of people who embark on them eventually regain the weight they lost – and often more. This phenomenon, known as weight cycling or yo-yo dieting, has puzzled many researchers. Despite one's strong willpower and determination, the body's innate hormonal mechanisms fiercely resist prolonged restriction, leading to physiological changes that favour weight regain.

Hormonal Havoc

When we drastically reduce our caloric intake, the body perceives it as a threat to survival. In response, hormonal systems, such as leptin and ghrelin, swing into action. Leptin, the hormone responsible for regulating hunger and satiety, decreases during dieting, sending signals to the brain that starvation is imminent. This reduction in leptin triggers an increase in appetite and a decrease in metabolic rate, making weight loss challenging. Meanwhile, ghrelin, one of a number of hormones that stimulate appetite, increases, intensifying cravings for high-calorie foods. This hormonal imbalance persists even after the diet ends, creating a perfect storm for weight regain.

Furthermore, the body's response to caloric restriction extends beyond leptin and ghrelin. Hormones such as insulin, cortisol, and thyroid hormones also play essential roles in maintaining metabolic balance. For example, during a diet, insulin levels decrease, which can lead to increased fat storage when normal eating patterns resume. Cortisol, the stress hormone, rises in response to the body's perceived threat, further promoting fat storage and sabotaging weight loss efforts. Additionally, thyroid hormones, which regulate metabolism, decrease during caloric restriction, slowing down the body's energy expenditure.

Metabolic Adaptation

In addition to hormonal changes, the body also undergoes metabolic adaptations during and after dieting. As caloric intake decreases, the body slows down its metabolism to conserve energy. This means fewer calories are burned at rest, making it increasingly challenging to maintain weight loss. Furthermore, the loss of muscle mass during dieting further hampers metabolic rate, as muscles play a crucial role in calorie expenditure. Consequently, once the diet ends, the body's reduced metabolic rate makes it incredibly easy to regain the lost weight.

The body's ability to adapt to reduced caloric intake is a survival mechanism that has evolved over thousands of years. Our ancestors faced periods of famine, and the body's ability to conserve energy and store fat was vital for survival. However, in the modern world of readily available food, this adaptive response becomes a hindrance to sustainable weight loss.

What is the Answer?

So while diets may promise quick fixes, they fail to address the intricate hormonal mechanisms and metabolic adaptations that contribute to weight regain. Rather than focusing on short-term restrictive approaches, a sustainable lifestyle that incorporates balanced nutrition, regular physical activity, and a positive mindset is key to achieving long-term weight management and overall well-being.

For some individuals, we can bring medications or surgery in to attempt to counteract the mechanisms above.

By understanding the complex interplay of hormones and metabolic processes, we can make informed choices and break free from the fad dieting cycle.