Dark chocolate is rich in cocoa solids, which contain compounds known as flavonolds. At high levels, cocoa flavanols have been shown to help lower blood pressure and cholesterol, improve cognition and possibly lower the risk of diabetes. But limit your portions to about 1 ounce a day.
When it comes to fat and calories, some cheeses are lighter than others. Experts recommend using it as a flavor enhancer rather than as the focus of a meal.
Granola contains healthy ingredients such as oats, nuts and dried fruit, and it can serve as a tasty topping to yogurt or cereal. But since it can pack up to 600 calories per cup (thanks to sugar and other ingredient treats), it's important to sprinkle, not pour.
Ready-to-eat breakfast cereal can make for a convenient and healthy breakfast, especially if it's made with whole grains, is low in sugar and is served with fresh fruit and low-fat milk. But sugary cereals that lack fiber and protein can cause a blood sugar spike and crash before lunchtime.
Order a California roll, and you'll get heart-healthy monounsaturated fats from avocado and zinc from crab, all for 255 calories. But a crunchy shrimp tempura roll, which is battered and fried and often drizzled with spicy mayo, has about 200 more calories and three times the amount of fat.
Air-popped popcorn is a healthy, whole-grain, antioxidant-rich snack that's low in calories. But movie theater popcorn, which is popped in coconut oil, is a diet disaster, contributing 1,200 calories and about three days worth of saturated fat for a medium bucket -- and that's without the buttery topping.
A Greek yogurt with no added sugar makes for a filling protein- and calcium-rich snack. But sweetened yogurts with flavorings or fruit purees have less protein and are more like dessert, with up to 8 teaspoons of sugar.
Energy bars can be a wise choice for a snack or mini meal if they offer a healthy dose of protein and fiber, and are low in sugars and saturated fat. But when they contain chocolate coatings or sugary syrups, they can pass for protein-fortified candy bars.
A salad made with spinach, light tuna, veggies, feta and yogurt dressing can make for a low-calorie, nutrient-rich lunch. But when your salad contains crispy chicken, bacon, cheddar and ranch dressing, you'd be better off eating a burger.
If you are vegetarian, peanut butter can be a convenient way to add protein and heart-healthy fats to your diet. Just steer clear of flavored peanut butters with sugar and cocoa butter, which can quickly turn your passion for peanut butter into consumption of calorie-rich chocolate.
When I first studied nutritional science, all calories were considered "equal" when it came to weight loss. The time of day you ate didn't matter as long as you were eating the appropriate amount of calories for your goals.
But as our understanding of nutrition has evolved, we've learned that eating earlier in the day can be more favorable for shedding pounds, while eating later can interfere with weight loss -- and for more than one reason.
For one, eating during the evening often goes hand in hand with mindless nibbling. Think of how many times you may have reached for a handful of pretzels, chips or M&Ms while watching TV or Netflix at night. Evenings can also be filled with unstructured time, which means eating may fill a "void"; if you're bored, it's easy to indulge in high-fat, sugary foods when you don't have to focus on other tasks such as work or errands.
To be clear, over-consuming calories at any time of day will result in weight gain. But many nutritionists, myself included, have noticed that clients fare better when they're consuming most of their calories earlier in the day. That way, by the time evening rolls around, they're more satiated and may be less likely to overindulge in a box of chips or cookies, a few too many spoons of ice cream or a few glasses of wine.
And then there's the fact that more research has shown how our bodies respond to front-loading calories during our waking hours versus consuming them later on.
It has to do with the complex science of circadian rhythms -- physical, mental and behavioral changes in the body that follow a roughly 24-hour cycle. These rhythms are driven by a master biological clock in the brain that is primarily influenced by light and tells other "peripheral" clocks in the muscles and organs what time of day it is.
Because circadian rhythms affect how calories, carbohydrates and fats are metabolized over a 24-hour period, they can help explain why eating late at night decreases the rate at which we lose weight, as a 2015 study found.
The study involved 420 overweight and obese participants who were divided into two groups: early eaters and late eaters. The early eaters ate lunch before 3 p.m., and the late eaters consumed lunch after 3 p.m. The late lunch group also ate lower-calorie breakfasts, or skipped breakfast more often than early eaters.
At the end of the 20-week study period, the late eaters lost less weight compared with the earlier eaters (17 vs. 22 pounds on average, respectively) and lost their weight more slowly, despite the fact that both groups ate approximately 1,400 calories per day and consumed similar amounts of fat, protein and carbohydrates.
The research suggests that the calories we burn from digesting, absorbing and metabolizing the nutrients in the food we eat -- known as diet-induced thermogenesis -- are influenced by our circadian system, and are lower at 8 p.m. than at 8 a.m.
To put this into practice, especially if you are trying to lose weight, try to front-load your calories as much as possible. Don't skip breakfast, and consider having what you would typically eat for dinner during lunchtime. Think grilled fish or chicken with veggies and quinoa. Then, at dinner, eat half of what you would typically consume, or consider cutting carbs to help downsize your meal.
Night-shift workers can also benefit from eating in sync with their circadian rhythms. They may modify meal timing by eating their heaviest meal when they wake up, about 3 or 4 p.m., and eating a light "breakfast" at the end of their workday, at 7 or 8 a.m.
And if nighttime nibbling is a problem for you, here's a tip that's worked well with my clients: "Close the kitchen" at a specific time each evening. You can use your smartphone to set an alarm to remind yourself when it's time. Then, situate yourself where you can't see the fridge, and keep yourself busy with other activities that will take your mind off food, like calling a friend, reading a magazine or book, polishing your nails or taking a bath.