Why do I sometimes not lose weight despite regular physical activity?

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Exercise has many health benefits, but sometimes the only benefit sought is simply weight loss.

In this case, there is nothing more annoying than being diligent and disciplined in your exercise routine only to discover at the end of the week that you haven't lost a single kilo, or worse, that you've even gained a little weight! But before you throw your scale out the window, know that all is not lost. Appearances can be deceptive, and it could well be that all that physical exercise is doing you more good than you think!

So... if appearances are deceptive, why isn't your weight decreasing?

Weight varies greatly

Your weight increases and decreases naturally. In the course of a single day, it can vary by two or three kilos depending on when you weigh yourself! ¹ Since it takes about 3,500 calories to gain 500g of fat, it's impossible for you to have gained all that weight in one day. The scale is a great indicator, but it reflects your "weight," which should not be confused with body fat. At times, our bodies may contain more water, thus increasing the number on the scale, but this does not mean we have gained "fat."

You gain muscle while losing weight

People who exercise are more likely to gain muscle mass, and this can show up on the scale.
But not everyone carries their weight the same way: if you look at two people of the same height and weight, their appearance can be very different. This is due to several factors (water retention, body composition, and overall silhouette), but notably to the fact that muscle and fat have very different densities. We often hear that muscle weighs more than fat. This is false. A kilogram of muscle and a kilogram of fat weigh the same. But aesthetically, they do not look the same. For example, a kilogram of cotton will physically appear larger than a kilogram of steel.

You don't watch your diet

It's not always a factor, but you may be unknowingly consuming more calories than you need. It's a common misconception that if you exercise more, you can eat more, and to some extent, that's perfectly true. You do need more calories to fuel your body if you exercise often... but you don't always need to eat a LOT more. Aim for foods that are high in protein. Studies have shown that they have a longer-lasting satiety effect, and they're more likely to help you lose weight over time. ²

You are not eating whole foods

Whole foods are rich in vitamins and minerals, contain no chemical additives, and are generally unprocessed. Some examples include apples, bananas, broccoli, tomatoes, brown rice, whole eggs, and salmon. Because these foods are highly nutritious, they provide our bodies with what they need to function optimally. Conversely, a diet high in processed foods can slow weight loss in several ways. First, these foods often lack iron, which is needed to transport oxygen throughout the body. This can limit your ability to burn calories while exercising. ³ Additionally, unprocessed foods don't contain refined sugars, which have been linked to obesity. These sugars have also been shown to increase the production of ghrelin, the hunger hormone, which reduces your brain's ability to generate feelings of fullness. ³

You don't do any weight training/resistance training

The health benefits of exercise are most evident when you combine different types of physical training. We often tend to think that if we spend all our time doing cardio, that's enough. But you can give your muscles a much better workout (and therefore promote weight loss) by combining your regular exercise with strength training or resistance training. While a strength training session won't burn as many calories as a cardio workout, it's more effective at building muscle mass. Over the course of a day, muscle burns more energy than fat, so the more muscle you have, the more calories you'll burn, even when you're not doing anything! ⁴

You don't do cardio

The opposite is also true. Strength training and bodyweight-based resistance exercises are great for building strength, but overall, cardio training burns more calories per session. Evidence suggests that cardio is what makes you fitter and helps boost your metabolism, leading to better weight loss in the long run. ⁵

You are not getting enough sleep

Studies have shown that lack of sleep can have a direct impact on our ability to lose weight, as the biological mechanisms that come into play when we are tired cause us to feel hungry and eat more than we need in order to receive a quick energy boost. ⁶ Additionally, studies suggest that your metabolism cannot function optimally if you are tired during the day, ⁷ So even if you can resist the chocolate cookies, your body won't burn the calories like it normally would.

All this to say that daily or even weekly weight fluctuations are nothing to worry about and are perfectly normal, even if they can sometimes be frustrating! If you eat healthily, get enough varied exercise, and sleep well, the previously stuck needle on the scale will soon start to tip in your direction. And remember, the scale is just one way to measure your progress. You can take your measurements every month to see how your figure is changing, pay attention to how you feel in your clothes, and most importantly, see how much better you feel.

1. https://health.clevelandclinic.org/when-is-the-best-time-to-weigh-yourself/ [ ↩ ]
2. https://academic.oup.com/ajcn/article/101/6/1320S/4564492?login=true [ ↩ ]
3. https://www.ncbi.nlm.nih.gov/books/NBK54103/ [ ↩ ] [ ↩ ]
4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2980962/ [ ↩ ]
5. https://www.sciencedirect.com/science/article/abs/pii/S1521691804000836 [ ↩ ]
6. https://link.springer.com/article/10.1007%252Fs13679-012-0026-7 [ ↩ ]
7. http://www.tgiscience.com/documents/Sleep%20and%20Weight%20Gain.pdf [ ↩ ]