Keeping your weight under control is a daily challenge for many of us. Faced with a multitude of “miracle” tips, the idea that simply exercising could be enough to eliminate all excess weight is particularly appealing. However, the reality is more complex: while exercise plays a major role in energy expenditure and muscle building, it cannot work effectively without a proper diet.

Understanding energy balance

Basal metabolic rate is the amount of energy your body needs at rest to perform its vital functions (breathing, digestion, blood circulation, etc.). In other words, even if you lie down all day, you still burn calories. For example, for a 45-year-old woman who is 5'5" and weighs 132 pounds, the basal metabolic rate is estimated at around 1,400 kcal per day.

Added to this is energy expenditure related to activity: cycling, yoga, jogging, etc. The longer and/or more intense the activity, the more it increases your energy expenditure and, therefore, your total calorie requirement.

Total energy requirements = Basal metabolic rate + Activity-related energy expenditure

To maintain your weight or lose weight, the principle is simple: your daily calorie intake must be equal to or less than your energy expenditure. So, if your requirements are 2,000 kcal and you consume 2,500, you will not lose weight, even if you exercise every day.

How exercise helps you lose weight

While exercise does not cause weight loss on its own, physical activity combined with a healthy diet has significant effects on our bodies.

Improved insulin sensitivity

Regular exercise helps your muscles to better absorb the sugar in your blood, which prevents it from being converted into fat and prevents insulin spikes that cause cravings and weight gain. [1, 2,3]

Appetite regulation

Moderate to high-intensity exercise can temporarily reduce hunger by influencing appetite hormones (ghrelin, leptin), which helps to better control calorie intake. [1,4]

Increased basal metabolic rate

Strength training builds muscle. The more muscle you have, the more calories your body burns at rest. This increases your basal metabolic rate, which makes it easier to lose weight. [1,5]

Regular exercise activates several key processes for weight loss, but its benefits are only fully realized if you also eat a balanced diet.

To lose weight sustainably, start by adopting healthy eating habits:

- Choose unprocessed, whole foods: fresh fruits and vegetables, whole grains, legumes, nuts, and seeds.
- Balance your plate: include a source of protein (meat, eggs, fish), a source of high-quality carbohydrates (quinoa, lentils, whole-grain pasta), and a source of vegetables.
- Manage your portions and listen to your hunger: take the time to eat, spend at least 20 minutes at the table, and chew your food. We have teeth, so let's use them!

In conclusion

Weight management is based on a balance between energy intake and expenditure, supported by a varied, high-quality diet and a physically active lifestyle. By adopting these principles gradually and sustainably, you give yourself the best chance of achieving and maintaining your ideal weight while taking care of your overall health.

Sources :

[1] Greenway, F. L. “Physiological Adaptations to Weight Loss and Factors Favouring Weight Regain.” International Journal of Obesity, vol. 39, no. 8, Aug. 2015, pp. 1188–96, https://doi.org/10.1038/ijo.2015.59.

[2] Reiner, Miriam, et al. “Long-Term Health Benefits of Physical Activity--a Systematic Review of Longitudinal Studies.” BMC Public Health, vol. 13, Sept. 2013, p. 813, https://doi.org/10.1186/1471-2458-13-813.

[3] Sigal, Ronald J., et al. “Effects of Aerobic Training, Resistance Training, or Both on Glycemic Control in Type 2 Diabetes: A Randomized Trial.” Annals of Internal Medicine, vol. 147, no. 6, Sept. 2007, pp. 357–69, https://doi.org/10.7326/0003-4819-147-6-200709180-00005.

[4] Flack, Kyle D., et al. “Exercise for Weight Loss: Further Evaluating Energy Compensation with Exercise.” Medicine and Science in Sports and Exercise, vol. 52, no. 11, Nov. 2020, pp. 2466–75, https://doi.org/10.1249/MSS.0000000000002376.

[5] McPherron, Alexandra C., et al. “Increasing Muscle Mass to Improve Metabolism.” Adipocyte, vol. 2, no. 2, Apr. 2013, pp. 92–98, https://doi.org/10.4161/adip.22500.