On HIIT 100s sets during Weeks 1-3, when rest periods are 30 seconds or more, perform the first three sets of 10 as fast and explosively as possible. This will help build more muscle power and strength, despite using such light weight. On Sets 4-6, keep the movement slow and controlled, focusing on the contraction and squeezing each rep at the top for one to two seconds. This helps establish a strong mind-muscle connection, which is critical for muscle size, shape, and separation.

A calorie isn’t always a calorie. Eating 100 calories of high fructose corn syrup, for example, can have a different effect on your body than eating 100 calories of broccoli. The trick for sustained weight loss is to ditch the foods that are packed with calories but don’t make you feel full (like candy) and replace them with foods that fill you up without being loaded with calories (like vegetables).

The next time you train that muscle group, decrease the starting weight by 5-10 pounds. If any of the HIIT 100s exercises are new to you, you'll need to spend some time figuring out how much weight you can do for 10 reps. The week before you start the HIIT 100s program, work these exercises into your training to get a gauge on appropriate weights. When estimating your 10RM, be sure to do the HIIT exercise first for that muscle group.

When you drink liquid carbs, like the sugar in soda, your body doesn't register them the same way as, say, a piece of bread, according to a review of studies published in Current Opinion in Clinical Nutrition & Metabolic Care. That means, even though you're taking in calories, your fullness cues aren't likely to signal that you're satisfied once you finish off a can. And that can lead to consuming more overall.
A 2018 study among more than 600 adults who were tracked for a year concluded that while there are different paths to weight loss, the advice to limit added sugars and refined grains, add more veggies to your plate, and eat more whole foods — in other words, focusing on the quality of your diet — is the way to go. People who followed this advice lost weight without worrying about calories.
If you’ve been eating fast food for years, get real about your approach: You’re probably not going to stick to an organic, gluten-free, paleo overhaul for very long. "You want to change as little as possible to create calorie deficit," says Dr. Seltzer, who insists the best way to support sustainable weight loss is to incorporate small changes into existing habits. So instead of giving up your daily BLT bagels in favor of an egg-white wrap, try ordering your sandwich on a lighter English muffin. Or say you eat a snack bar every afternoon: Swap your 300-calorie bar for a 150-calorie alternative. "Your brain will feel the same way about it, so you won’t feel deprived," he says.

"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.