For example, when it comes to hormones, ghrelin makes you hungry, leptin and other hormones keep you feeling full, Nadolsky says. Thyroid, cortisol, insulin, testosterone, and estrogen all influence how you metabolize and store energy. Meanwhile, genetics have a large influence on both basal metabolic rate (how many calories you burn just to live) and hormone health. While all of these things are impacted by our diet, they’re not only controlled by the way we eat. And, in fact, while sleep, stress management, and, when needed, medication can help regulate other hormone levels such as estrogen and thyroid, our hormones and other physiological processes are often out of our control. And by the way, being able to impact our hormone levels and metabolism with our diet doesn’t always work out in favor of weight loss. As a 2016 review notes, one of the reasons weight loss by way of caloric restriction isn’t efficacious is because “this strategy is countered by the body’s natural physiological response to negative energy balance.” In other words: The body fights back against caloric restriction.
On the physiological side of things, it’s important to realize that the vast majority of your daily caloric burn comes down to just basic functions like breathing and keeping your heart beating, Moore says. Called your basal metabolic rate (BMR), your muscle does play a role in setting it, but extra muscle isn’t going to turn you into a supercharged calorie-torching machine. And even though exercise does burn calories, that total is often significantly less than what we expect and would need to create a large daily caloric deficit, he says.
“Starting slow and working your way up is better than overdoing it and giving up,” says Gagliardi. “I like the idea of attaching the new behavior of taking a walk to an existing behavior.” An easy way to approach it: Commit to going for a quick 10-minute walk after dinner, and slowly increase the time as you become more comfortable with daily movement.
"One of the hardest parts of losing weight is maintaining the lifestyle changes you’ve made. It’s difficult to stay motivated all the time, especially if you’ve slipped up along the way. But don’t let this affect your end goal. If you’re feeling particularly unmotivated, ask a friend to join you for your workout and then afterwards cook something healthy for dinner together."
"If your diet consists of lots of sports drinks, sugar-sweetened drinks like fizzy pop and flavoured waters, or sugary foods like chocolate and cakes, it will make losing weight harder. While whole fruits and vegetables are undoubtedly good for you, they can also sometimes cause weight gain if you eat too much, as they have high levels of natural sugars in them. Low-fat food options might have high amounts of added sugar in there too, so make sure to check the food label.