Do you feel like you eat well, exercise regularly, and still don’t see changes in your body? This is a common source of frustration for many people. And far from being a matter of willpower or not trying “hard enough”, the underlying causes may be physiological, hormonal, or emotional.
As a nutritionist, I see this pattern frequently in clinic: individuals who are committed to their health, but feel like their body simply isn’t responding. And here’s the truth — our bodies don’t operate like calorie calculators. Fat loss is influenced by a number of interconnected factors that we need to address. our body does not work like a calorie calculator, and there are many factors that can influence fat loss and what we should look out for.
1. Hypothyroidism and Hormonal Imbalances
The thyroid gland plays a key role in regulating metabolism, body temperature and energy levels. When it doesn’t produce enough thyroid hormones (a condition known as hypothyroidism), your body’s energy expenditure slows down, fluid retention increases, and symptoms like fatigue, constipation or feeling cold may appear.
While clinical hypothyroidism is diagnosed through blood tests (TSH, T3, T4), there’s also a subclinical form, where values are still within range but symptoms are present. This is especially common in women and can be influenced by stress, inflammation, and nutritional deficiencies (such as iodine, vitamin D, zinc, selenium or iron).
If you suspect this may be affecting you, it’s important to work with a qualified professional who will look beyond standard lab values — taking into account symptoms, deficiencies, and your medical history.
2. Gut Inflammation and Dysbiosis
Your gut microbiome is made up of thousands of bacterial strains, each with different roles — and it has a direct impact on overall health. These bacteria don’t just help digest food and produce nutrients: they also regulate immune function, produce neurotransmitters and influence metabolism.
When the balance of your microbiota is disrupted (known as dysbiosis), beneficial bacteria decrease while inflammatory or gas-producing strains dominate. This can lead to bloating, poor nutrient absorption, and increased intestinal permeability (commonly referred to as “leaky gut”).
Common causes of dysbiosis include:
Repeated use of antibiotics or antacids.
Chronic stress and nervous system dysregulation.
Diets low in fibre and protein, and high in ultra-processed foods or refined carbs.
Excessive alcohol consumption.
Lack of dietary diversity (monotonous eating habits).
This can contribute to low-grade systemic inflammation, increase insulin resistance, disrupt hunger and fullness cues, and promote abdominal fat storage. It can also affect your mood, since a significant portion of serotonin is produced in the gut.
3. Chronic Stress and Anxiety Disorders
Stress isn’t just mental: it’s a complex physiological stateregulated by the hypothalamic–pituitary–adrenal (HPA) axis. When you live in a state of constant alert, your body produces more cortisol, a hormone that can: raise blood sugar and insulin levels (promoting fat storage, especially around the abdomen); disrupt sleep quality; and affect your appetite and food choices.
Chronic stress also impacts thyroid function, suppresses sex hormone production, disrupts the menstrual cycle and weakens the immune system. It alters the gut microbiome too, making it harder to digest food, absorb nutrients, and maintain a healthy metabolism.
People with anxiety disorders may be under constant stress, even if they’re not aware of it. This often leads to physical symptoms like muscle tension, digestive issues, sleep disturbances or chronic fatigue — all of which can make fat loss more difficult.
On top of that, many people with anxiety use food to self-soothe, eating in response to emotions rather than hunger or satiety cues. This creates a vicious cycle of emotional eating and difficulty losing weight. the result is a vicious circle which hinders weight loss and increases emotional distress.
4. Overly Restrictive Diets
If you have tried a thousand and one restrictive diets like «the pineapple diet» or «the artichoke diet», let me tell you that the only thing you have probably achieved is being malnourished, losing fluids, muscle and fat which translates to a rapid drop on the scales.
Although it may seem ironic, eating too little can make us put on weight in the long term. This is mainly because when we «starve the body», our body is unable to tell the difference between a diet and a famine. Consequently, when it detects a very low energy intake, it activates survival mechanisms as explained below.
Furthermore, a very restrictive diet can in the long term cause micronutrient deficiencies that may end up affecting thyroid, cardiac and hepatic function, in many cases worsening metabolism itself. They are also associated with a greater risk of binge eating, anxiety around food, loss of muscle mass and disruption of hunger and satiety signals.
This is why my approach as a nutritionist focuses on nourishing the body — not punishing it. We work on helping the body feel safe again, moving out of survival mode. If you feel your health or metabolism has been affected, it’s worth consulting a registered nutrition professional. Teaching the body to trust again and stepping out of constant alert mode. Feel free to consult a nutrition professional if you feel your health and metabolism are compromised.
Most common survival mechanisms
- It reduces our energy expenditure: Imagine your body is like a mobile phone: if we only charge it up to 40% each day, it’s likely that – unless we switch on power-saving mode – it will eventually switch itself off. Our body does the same: «Well, if you give me fewer calories, I’ll have to cut back somewhere (reduced production of hormones and proteins, lower heart rate, etc.).» In the long term, this is a problem because we end up making our body need fewer calories to function, and on a social and emotional level, eating very little isn’t exactly feasible.
- Prioritise fat storageNow imagine your body as a traveller lost in a desert, not knowing when it will find food again. Instead of using up all the food it has found, it consumes the bare minimum and saves what it has for later. In the same way, your body stores a large part of the energy it receives in the form of fat, which is the most efficient and long-lasting fuel.
5. Healthy Eating That Isn’t Personalised
It’s essential to understand that for fat loss to occur, there needs to be a slight but consistent calorie deficit over time — meaning you consume less energy than you burn. Without this, even the most nutritious and balanced diet won’t lead to fat loss, as your body has no reason to dip into its fat stores. This is why working with a dietitian or nutritionist is so important — to ensure you meet your nutritional needs while creating an appropriate and sustainable energy deficit.
And remember: a flexible mindset is just as important. Fat loss should fit into your lifestyle — it should be compatible with your social life, relationships, and emotional wellbeing. Missing your deficit for a day won’t ruin your progress. Consistency over time is far more powerful than daily perfection.
English 
Spanish 
French