Why is it that losing weight doesn't work when you exercise a lot but eat poorly?

Weight loss doesn't work if you exercise a lot but eat poorly, because nutrition has a greater influence on the calorie balance than physical activity. Exercise burns calories, but an unhealthy diet can effortlessly undo that burn. The questions below explain why that works that way and what people can do to actually achieve results.

What has more influence on weight: diet or exercise?

Diet has more influence on weight than exercise. Research and clinical experience consistently point in the same direction: what a person eats determines the calorie balance for the most part, while sport plays a supportive but more limited role. An hour of intensive exercise burns an average of 400 to 600 kilocalories, an amount that is quickly regained with just one meal or snack.

This does not mean that exercise is pointless. Regular physical exercise improves insulin sensitivity, supports muscle maintenance during weight loss and has proven benefits for overall health. But if the diet is not in order, exercise rarely fully compensates for that.

A common saying in nutrition is that weight is determined about 80 percent in the kitchen and 20 percent in the gym. That ratio is a simplification, but the core message is right: anyone who structurally eats more calories than the body burns will not lose weight, no matter how much they exercise.

Why does exercising sometimes make you hungrier?

Exercise increases the appetite in many people because the body sends out signals to replenish the energy used. This is a physiological response: hormones such as ghrelin, the hunger hormone, rise after intense exertion. The consequence is that people eat more after exercising than they have burned, meaning the net calorie balance does not improve.

In addition, psychology plays a role. People who have just exercised consciously or unconsciously justify a larger meal or an extra snack as a reward. This mechanism, also known as the “license to eat” effect, undermines the calorie reduction that the workout should have produced.

Intensive workouts, such as interval training or strength training, appear to stimulate the appetite more strongly than moderate exercise such as walking. Anyone who finds that exercising leads to overeating may benefit from consciously planning meals around workouts and choosing protein-rich foods, which keep you full for longer.

What nutritional mistakes do athletes make most often?

The most common dietary mistakes made by people who exercise a lot but don’t lose weight are underestimating their calorie intake, overcompensating after training, and choosing foods that are considered healthy but are high in calories. Poor eating habits and exercise go hand in hand more often than people realise, precisely because exercise gives a false sense of compensation.

The most common mistakes at a glance:

• Using sports drinks and protein bars without necessity. These products are intended for endurance athletes or strength athletes with high energy needs. For the average athlete, they provide unnecessary calories.
• Justifying large portions after exercising. An hour’s workout rarely justifies a meal that’s twice as big as usual.
• Eating healthy products in large quantities. Nuts, avocado, wholegrain products and smoothies are nutritious, but also contain a lot of calories. Portion size remains relevant.
• Eating irregularly due to a busy schedule. People with a hectic lifestyle skip meals and compensate later with larger portions or unhealthy choices.
• Eating too little protein. Proteins support muscle recovery and satiety. A deficiency leads to increased hunger and less muscle preservation during weight loss.

How do sleep and stress affect weight loss?

Sleep deprivation and chronic stress make losing weight significantly harder, even for people who exercise a lot and eat consciously. Both factors disrupt hormone balance in ways that directly affect fat storage, appetite and energy expenditure. This is an underestimated component of the calorie balance.

What does sleep deprivation do to weight?

Inadequate sleep increases the level of ghrelin, the hormone that stimulates hunger, whilst leptin decreases, the hormone that signals satiety. As a result, sleep-deprived individuals experience a greater appetite, more frequently reach for high-calorie foods and have less energy to make conscious nutritional choices. Furthermore, the body recovers less effectively from training, which reduces the effectiveness of exercise.

What does stress do to weight?

Chronic stress raises cortisol levels in the blood. Cortisol promotes fat storage, particularly around the abdomen, and increases the craving for sugary and fatty foods as a quick source of energy. People under prolonged stress are more likely to eat emotionally and have less mental capacity to make structural lifestyle changes. Anyone who consistently gets too little sleep or is under a great deal of pressure will find that they are unable to lose weight, even with an active lifestyle.

When is medical guidance for weight loss useful?

Medical supervision for weight loss is useful when someone fails to achieve results despite adjustments to diet, exercise and lifestyle, or when being overweight is accompanied by health issues such as high blood pressure, elevated blood sugar or joint problems. In such cases, a doctor can assess whether underlying factors are at play and whether additional treatment is appropriate.

Not everyone who wants to lose weight needs medical supervision. But for people who cannot lose weight despite serious effort, a medical assessment offers insight into what is going on. Sometimes hormonal factors, medication use or metabolic disorders are an explanation for the lack of results.

GLP-1 medication is an example of a treatment that a doctor may consider for people who are overweight or obese. This medication can help with weight loss by reducing appetite and regulating blood sugar levels. Results vary from person to person, and a doctor will always assess whether a treatment is medically appropriate.

How does Wellumo help with weight loss?

Wellumo offers medical guidance for people who want to lose weight and wish to consult a doctor for this purpose, without having to visit a physical practice. The process is completely digital and discreet, with GMC-registered doctors who independently assess each application.

Here is how it works:

• The patient completes a medical initial questionnaire via the website
• A Dutch-registered medical doctor reviews the answers and determines whether a treatment is appropriate and medically sound
• Upon approval, the doctor issues a prescription, which is forwarded to the cooperating pharmacy
• Medication is delivered discreetly to your home, with the option of a subscription for repeat deliveries
• Not everyone is eligible; the doctor decides on a case-by-case basis

Wellumo communicates prices in advance and transparently, so that people know where they stand. For questions about the process or the possibilities, there is Is contact possible? via the website.