On a Weight-Loss Journey? Here's How Many Pounds You Can Expect to Lose in 3 Months

Although everyone's body is different, in general people can expect to lose one to two pounds a week if they are doing so in a healthy manner, Jim said. So for three months, or about 12 weeks, a healthy goal is 12 to 24 pounds.

Losing weight at this rate ensures that you'll keep it off for the long term. If you have more weight to lose (50 or more pounds), you may lose more weight in the first few weeks, but in general, about a pound or two a week is a healthy target.

Ahead, find out how to lose this amount of weight in three months.

Ultimately, losing weight is all about calories in, calories out. In order to lose weight, you have to burn more calories than you take in. "You have to create a deficit of 3,500 calories to lose one pound," Jim explained. "This can be done by burning extra calories through exercise or reducing your intake of calories, but the best way is to use a combination of both methods. This ensures that you're giving your body enough nutrients during periods of weight loss."

However, eating in a 3,500-calorie deficit doesn't guarantee an exact weight loss of one pound. There are a lot of other factors that impact how your body loses weight, including stress, sleep, and hormones.

Although you should eat in a calorie deficit, he doesn't recommend anyone eat fewer than 1,200 calories a day. And since calorie needs are highly individual from person to person, Jim recommends meeting with a registered dietitian if you can to assess your needs and your goals. If that's not a possibility, you can use this formula to calculate your ideal calorie deficit for weight loss.

"For weight loss, cardio is king," Jim said, adding that the American College of Sports Medicine (ACSM) recommends 300 minutes of cardio training a week for weight loss. "I would recommend low to moderate continuous exercise," he said.

If 300 minutes sounds like a lot, it doesn't have to equal vigorous HIIT training or an intense Spin class. Your cardio workout should be at least continuous cardio at a moderate level, reaching 60 to 70 percent of your max heart rate.

Running not your thing? Go for a brisk walk, swim laps, ride your bike around the neighbourhood, or jump rope — anything that will get your heart rate up and make you break a sweat.

Cardio is essential for weight loss, but you shouldn't ignore strength training. Not only does lifting weights burn calories, but building lean muscle will help you burn more calories at rest. "I would recommend two days of strength training a week of full-body exercises for maintenance," he said. If you want to bump that up, Jillian Michaels recommends weight training up to four times a week.

But if you're tracking your progress simply from the scale, you may not notice it budging much each week if you strength train more often. As you build muscle, it will change your body composition, but the number on the scale may stay the same. That's why it's important to track your progress using other methods such as measurements, how your clothes fit, and before-and-after photos.