Weight loss can be a long—and at times frustrating—journey, depending on your health condition, fitness level and goals at the start. Seeing the results of your hard work will spur you to keep going. But how long does it take for weight loss to become noticeable to you and to other people? Health experts explain below.

How Long Does It Take for Others to Notice Weight Loss?

Dr. W. Scott Butsch, director of obesity medicine at the Bariatric and Metabolic Institute of the Cleveland Clinic, told Newsweek that it depends on the amount of weight lost.

Health benefits occur with 5 to 7 percent body weight loss and this is probably where we begin to see changes in the appearance of others."

This amount of weight loss usually takes a few months but it can vary, in part because "the distribution of our weight, or body fat, varies among people of different ages, gender and ethnicities," Butsch said.

For example, pre-menopausal women hold their weight in their hips and thighs while men and post-menopausal women hold it more centrally in the belly. In addition, some may lose weight in their faces, which to others may be more noticeable than weight lost from hips or the waist.

How Long Does It Take for You to Notice Weight Loss?

It can actually take longer for you to notice your own weight loss than for other people to spot it, because we typically underestimate our own body size and weight, according to Butsch.

"Studies have shown that we are less accurately estimating our own body size and the changes in our body weight. However, this may depend on the individual as people lose weight from different areas of their bodies," he said.

Those who hold their weight mostly in the waist area, as is the case with men, may notice a change in how their trousers fit or that they're using a different notch on their belt.

Guzman said weight loss was typically noticed in our faces first. According to a Canadian study on the social perception of weight loss, "women and men of average height need to lose or gain approximately 10 pounds for anyone to notice the difference in a face," he said.

How much weight a person needs to lose for it to be noticeable is also subjective as it depends on your frame and starting body mass index, according to Guzman.

On average, a 15 to 20-pound loss (approximately 2 to 5 percent of your starting body weight) is enough to notice "significant changes in your body," he said.

You can start seeing differences in yourself as early as two weeks with rapid weight loss. However, most people will notice a significant difference in themselves anywhere between four to eight weeks, Guzman said.

"Keep in mind that without medical supervision, 1 to 2 pounds a week of weight loss is the healthiest alternative. Weight loss may be more drastic and noticeable in a shorter period with medical supervision."