Spanish longevity doctor warns against losing more than 850 grams per week

Spanish doctor David Céspedes, an expert in longevity and functional health, cautions against the dangers of rapid weight loss, emphasizing that a healthy weekly loss should not exceed 850 grams. Céspedes, known on social media as @dr.davidcespedes, highlighted these risks during a participation in the BBVA Aprendemos Juntos cycle.

He explained that rapid weight reduction often results in a significant loss of muscle mass rather than just body fat. Furthermore, severe caloric restrictions can lead to deficiencies in essential vitamins and minerals, chronic fatigue, and hormonal disruptions. Céspedes stressed the importance of sustainable weight management over quick fixes.

During a conference, Céspedes outlined four primary factors that complicate weight loss. The first is basal metabolism, where the body conserves energy by reducing its expenditure during caloric restriction. The second factor is sleep quality; he noted that poor sleep in Western countries increases cravings for sugary and ultra-processed foods.

The third and most crucial factor, according to Céspedes, is daily physical activity outside of formal exercise. He cited a study at Guadalajara Hospital, Spain, showing that reduced movement, like not fetching medical histories, can decrease daily energy expenditure by about 500 kilocalories, potentially leading to a 7-8 kilogram weight gain over time. The fourth factor is cortisol, the stress hormone, which can trigger glucose release and subsequent increased appetite if the energy isn't consumed through activity.

Céspedes advocates for "eating well, not less," advising against overly restrictive diets. He believes a balanced approach focusing on nutrient-dense foods and consistent, non-exercise activity thermogenesis (NEAT) is key to long-term health and weight management.