A 2012 study also showed that people on a low-carb diet burned 300 more calories a day – while resting! According to one of the Harvard professors behind the study this advantage “would equal the number of calories typically burned in an hour of moderate-intensity physical activity”. Imagine that: an entire bonus hour of exercise every day, without actually exercising. A later, even larger and more carefully conducted study confirmed the effect, with different groups of people on low-carb diets burning an average of between 200 and almost 500 extra calories per day.
The upshot of all these chemicals floating around is big trouble for big-bellied guys. In a study at the University of Alabama at Birmingham, researchers took 137 men of all ages and sizes and used seven different measurements to determine their risks of cardiovascular disease. The single best sign of multiple heart-disease risks? No, it wasn't the guys' family histories or their cholesterol profiles. It was the amount of abdominal fat they carried.
We often make the wrong trade-offs. Many of us make the mistake of swapping fat for the empty calories of sugar and refined carbohydrates. Instead of eating whole-fat yoghurt, for example, we eat low- or no-fat versions that are packed with sugar to make up for the loss of taste. Or we swap our fatty breakfast bacon for a muffin or donut that causes rapid spikes in blood sugar.
Skimp on fluids, and your body will release an antidiuretic hormone that leads to water retention that could affect the scale, Dr. Setlzer says. While this sneaky effect is one reason why the scale is a poor measure of body mass loss, you can outsmart it by drinking more—particularly if you fill your glass with water or non-calorie alternatives like unsweetened coffee and tea.
Even if you do meet your goal, it's nearly impossible to keep off the weight over the long term: "The amount of restriction required [to maintain that number] will make you so hungry that you’ll eat everything in sight—it’s survival instinct," Dr. Seltzer says. And since calorie restriction gradually slows your metabolism, your body will be less prepared to burn the foods you binge on, he adds. That could mean gaining more pounds than you lost in the first place.
"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.