Focusing on healthy eating while overlooking physical activity is not so much a myth as an uncomfortable truth that many of us prefer to ignore. Yet the rapid rise in sedentary lifestyles and metabolic diseases, with their harmful consequences for both individuals and society, is difficult to overlook.
Myth: If you eat a healthy diet, you don’t need to exercise.
Whether our goal is to lose weight, build muscle, or simply maintain good physical fitness, combining a balanced diet with an active lifestyle is essential. The question we should ask more often is not how long we live, but how well we live. Quality of life—shaped by choices the effects of which are felt many years later—deserves a higher place among our priorities.
Physical activity refers to any bodily movement produced by the voluntary contraction of skeletal muscles that increases energy expenditure above the basal level. Physical activity can be divided into three intensity levels: light (such as leisurely walking or doing household chores), moderate (such as brisk walking or gardening), and vigorous (such as running, playing sports, or shoveling snow from a driveway).
Physical activity reduces the incidence of cardiovascular disease, including stroke and heart failure, lowers blood pressure, helps prevent weight gain, and improves blood lipid profiles. The European Association for the Study of the Liver highlights the role of an active lifestyle in the prevention and treatment of non-alcoholic fatty liver disease, as well as in reducing the risk of liver cancer (Baumeister, Schlesinger et al., 2019). The European Association for the Study of Diabetes emphasises that just 20 minutes of brisk walking each day can reduce the risk of type 2 diabetes by 19%. According to the World Health Organization, regular physical activity also improves muscle and bone health, reduces the risk of falls and fractures, supports mental health by alleviating symptoms of depression and anxiety, and enhances sleep quality.
In search of balance
When it comes to weight management, dietary habits play the more important role in the balance between calorie intake and energy expenditure. For example, an 80 kg adult who runs for 30 minutes burns approximately 300 kilocalories, while a single slice of pizza provides about 250 kcal. Fortunately, weight management is not simply a matter of adding and subtracting calories. Other factors, including hormonal and genetic influences, also play a role in the body’s energy balance. Basal metabolic rate refers to the amount of energy the body requires to maintain its vital functions at rest. Most of the calories we burn each day are used for this purpose—that is, they are expended passively, without any conscious effort on our part. And the greater your muscle mass, the higher your basal metabolic rate, making it easier to burn the calories from those few slices of pizza.
The primary macronutrients in food are carbohydrates, fats, and proteins. Carbohydrates are stored in the body as glycogen, which is found primarily in skeletal muscle and, to a lesser extent, in the liver (Jensen, Rustad et al., 2011). Once glycogen stores are full, excess glucose is converted into fat and deposited in the liver or around other internal organs, forming what is known as visceral fat. Visceral fat is associated with health problems such as insulin resistance, type 2 diabetes, and cardiovascular disease. The greater our muscle mass, the more glycogen we can store, thereby reducing the risk of developing these conditions.
Appetite—the desire to eat—is also closely linked to physical activity. Two hormones that have received increasing attention in recent years, ghrelin (often called the “hunger hormone,” produced by cells in the stomach) and leptin (produced by fat cells), play key roles in regulating appetite. Although this area is not yet fully understood, evidence suggests that moderate and vigorous physical activity can reduce appetite by influencing the action of these two hormones. This is yet another indication that nutrition and exercise can only be understood together, not in isolation (Gleason, Aboul-Enein et al., 2018).
A healthy lifestyle is a multidisciplinary field that may seem complex at first glance. Yet with a few well-established principles and consistent habits, it becomes an achievable goal. The quality of life we want—not only today but also 20 years from now—should guide the choices we make every day.
References
- Baumeister, S. E., Schlesinger, S., et al. (2019), “Association between physical activity and risk of hepatobiliary cancers: A multinational cohort study”, in Journal of Hepatology, vol. 70, no. 5, pp. 885–892.
- EASL, EASD, EASO (2016) – European Association for the Study of the Liver (EASL), European Association for the Study of Diabetes (EASD) and European Association for the Study of Obesity (EASO) (2016), “EASL–EASD–EASO Clinical Practice Guidelines for the management of non-alcoholic fatty liver disease”, in Journal of Hepatology, vol. 64, no. 6, pp. 1388–1402.
- Gleason, M., Aboul-Enein, B. H., et al. (2018), “Effects of exercise on appetite-regulating hormones, perceived hunger, and energy intake: A narrative overview”, in Central European Journal of Sport Sciences and Medicine, vol. 22, no. 2, pp. 5–12.
- Jensen, J., Rustad, P. I., et al. (2011), “The role of skeletal muscle glycogen breakdown for regulation of insulin sensitivity by exercise”, in Frontiers in Physiology, vol. 2, art. no. 112.
- Piercy, K. L., și Troiano, R. P. (2018), “Physical activity guidelines for Americans from the US Department of Health and Human Services”, in Circulation: Cardiovascular Quality and Outcomes, vol. 11, no. 11, art. no. e005263.
