Weight loss diets are among the most searched topics on the internet. Low-carb, intermittent fasting, ketogenic diets, detox… all promise quick results. However, studies and clinical experience show that, in most cases, the weight lost returns—and sometimes with a few extra pounds.

Why do diets fail so often? The answer isn't simply a lack of motivation. According to the principles of Functional Nutrition, failure is often linked to underlying causes that aren't taken into account when developing conventional diets.

The Calorie Myth: Not All Calories Are Created Equal

Most weight-loss diets focus on creating a calorie deficit—that is, eating less than you burn. While energy balance is important, this approach ignores a key point: food quality is as important as quantity. 150 calories of soda have a completely different effect on the body than 150 calories of fresh fruit.

The truth is, in most cases, "we don't need to eat less, we need to eat better." A plate of real food, rich in fiber, protein, healthy fats, and antioxidants , promotes satiety, regulates blood sugar, and maintains hormonal balance—effects very different from empty calories from sugar or ultra-processed foods.

Lack of personalization of diets: every body is unique

Another reason so many diets fail is the "one-size-fits-all" approach. However, each person has a unique lifestyle, genetics, metabolism, gut microbiota, and health history, all of which need to be considered.

For example, a high-fat diet can be beneficial for those who metabolize lipids well, but harmful for those with gallbladder problems. Similarly, high intakes of certain fibers can be a good option for regulating intestinal transit, but can cause pain, gas, and bloating in people with Irritable Bowel Syndrome (IBS).

In Functional Nutrition, meal plans are personalized after a detailed evaluation of laboratory tests, medical history and lifestyle.

Hormones that block weight loss

Often, the problem isn't a lack of effort or discipline. Even with restrictive diets, weight loss can be hampered by hormonal imbalances, which aren't always easy to diagnose.

The most common imbalances include:

• Insulin resistance : makes the weight loss process difficult;

• Subclinical hypothyroidism : decreases basal metabolism, making weight loss slower;

• Excess cortisol: increases appetite and promotes the accumulation of abdominal fat.

Without correcting these hormonal changes, any diet will have limited results.

Chronic inflammation and gut health

An inflamed body is a body resistant to weight loss. Chronic low-grade inflammation can have several origins:

• Diet rich in sugars, refined flours and processed vegetable oils;

• Food sensitivities (gluten, dairy, additives);

• Intestinal imbalance, also called dysbiosis, is often aggravated by antibiotics, stress, and poor-quality nutrition.

These conditions affect hormones like leptin, which regulates satiety, and promote fat accumulation. Restoring gut health —with prebiotic fibers, probiotics, and a reduction in inflammatory foods—is essential for functional weight loss.

The role of the liver in weight loss

The liver is responsible for metabolizing fats, hormones, and toxins. Common diets rarely consider how an overworked liver can hinder weight loss. To support liver function , it's essential to reduce or eliminate factors that impair it and include substances that nourish the liver.

Without this support, toxins released by fat mobilization can cause symptoms such as fatigue, headaches, and weight loss stagnation.

Stress, emotions, and sleep: the invisible saboteurs of diets

Even with a balanced diet, chronic stress, difficulties in emotional management — particularly emotional hunger — and poor sleep quality can hinder results:

• Cortisol elevated by stress increases appetite, promotes the accumulation of abdominal fat and worsens insulin resistance;

• Sleeping less than 7 hours alters hunger hormones (ghrelin and leptin), leading to greater calorie consumption the following day;

In everyday life, strategies such as meditation, deep breathing, regular physical activity, and structured sleep routines help to neutralize these effects.

Restrictive diets and lack of behavioral change

Overly restrictive diets lead to frustration and are rarely sustainable. When they end, even with positive results, old eating habits tend to return—and with them, the weight.

In Functional Nutrition, I practice an educational and progressive approach, transforming weight loss into a sustainable lifestyle, not just a “temporary project.”

How Functional Nutrition Enhances Healthy Weight Loss

1. Assess the complete clinical history : sleep, stress, emotional management, physical activity and health history;

2. Identify hidden causes , for example through evaluation of biochemical analyses and gastrointestinal health;

3. Personalize the meal plan , adapting it to the individual profile;

4. Correct nutritional deficiencies through targeted nutrition and supplementation;

5. Include stress management , sleep and movement as pillars of the plan;

6. Promote autonomy , teaching people to make conscious and sustainable decisions.

Conclusion: losing weight is restoring balance

Weight loss diets often fail because they only treat the symptom—excess weight—and ignore the root causes.

With Functional Nutrition, we adopt an integrative approach, viewing the body as an interconnected system. The goal is not just to lose weight, but to restore balance, reduce inflammation, regulate hormones, and nourish the body. Thus, weight loss becomes a natural consequence of a healthy and harmonious body.

If you're looking for healthy, lasting weight loss, schedule your Functional Nutrition consultation at Bioself. It may not be the quickest path, but it will be the most solid and sustainable.