During the process of losing weight itself the scale is probably the least effective tool for measurement.
Another problem with the scale is that pounds fluctuate on a daily, even an hourly basis. Depending on what a person eats or drinks, hormones, bowel movements, and even dehydration can alter an accurate weight measurement up to 5lbs.
Three More Effective Ways to Measure Weight Loss Progress
1. Tape Measurements
Taking measurements is the easiest way to measure progress. Most people have a soft tape measure, from a sewing kit, or they can be purchased 3/pack for $1. Tape measurements are somewhat effective because even a 1/4 inch gained or lost takes a long time to happen. A big meal will not cause you to gain an inch, and a week not working out won't cause an inch loss in muscle. Tape measurements are also very easy because it's a simple matter of placing the measuring tape around the body parts you wish to monitor, opposed to body fat calipers which are more expensive and harder to figure out.
The disadvantage with tape measurements is that they don't differentiate between fat and muscle, but it won't matter much as explained above because muscle mass doesn't grow that quickly it should be reasonably accurate.
2. How Clothing Fits
Many people don't actually care about accurate readings of their progress because their main goal is to feel good. A big goal to their "feeling good" is fitting better in their clothes - as well as feeling more energetic and confident. This is a great and healthy way to determine success without the stress of "the big weigh-in, measurement day." The only downside to this technique is that clothes do tend to stretch. If someone is using the same pair of gym pants to determine their progress, they may think they are losing weight when in fact, it's only the pants losing its elasticity. When using this method it's better to try fitting in to something that's a little too tight to start, such as a formal dress, pants with a specific belt size, or your old skinny jeans from college / high school.
3. Body Fat Scales
These days body fat scales can be purchased for home use. Typically they are built in combination with a digital weight scale. A scale that measures body fat usually has programmable features to save readings for multiple users. Body fat measurements are taken by sending a harmless electrical current through the body. The electricity can go through muscle more easily than fat. The amount of resistance to the current measures the amount of fat-free mass in a person's body.
People who track their calorie intake and exercise levels are twice as likely to succeed in their exercise goals.