Metabolism: losing weight and keeping it off

Losing weight may be tough, but keeping it off, as many people have experienced, can be much harder. However, it may not be for the reasons you think! While losing bodyfat is often relatively
straightforward in the short term, preventing that weight from simply coming back again much more challenging.

According to the University of Michigan, about 90% of people who lose significant amounts of weight, whether through diets, structured programs or even drastic steps such as gastric surgery,
ultimately regain just about all of it. They believe that the answer to why this happens lies with our metabolism, or the balance of energy in VS energy out.

When someone begins a new restrictive diet, their metabolism slows down, because they are suddenly consuming less calories. Their body responds by burning calories at a slower pace. As a
result, people will notice an initial drop in weight, but over time, will see less and less. The same can be said for when you increase the amount you eat as well – as you increase your food intake, your metabolism speeds up! This may seem like it is untrue, as people that continually put on weight generally feel like it is because their metabolism “is too slow”, however it is more often the case that they are simply just eating more calories than what their metabolism has increased to. The way I always like to explain weight loss maintenance to people is this: your metabolism will go
up or down to match what is going in. To lose weight, you need to have more calories going out than in. It stands to reason that over time, you can increase your metabolism by consistently eating
higher amounts of food. To make sure that this doesn’t also lead to you increasing your weight, you can make up the difference with exercise to consistently make sure your calorie output is higher
than what is going in!

There is also a lot of talk about our metabolism slowing down as we get older, and that this also leads to increased difficulty in losing weight, then keeping it off. Studies have shown that between
the ages of 20 and 60 our metabolism stays almost completely stable, even during major hormonal shifts such as pregnancy and menopause. Based on the data from these studies, a woman of 50 will burn calories just as effectively as a woman of 20.

If the calories we burn stay largely the same through life, the real source of obesity has to be the amount we’re eating, and the amount (or lack) or exercise we are doing! So what does this mean?
Much of the ageing process, and the commonly observed middle-aged weight gain, is not because of declining metabolism but genetics, hormone changes and lifestyle factors such as stress, sleep,
smoking and, perhaps most crucially, diet.