A smaller tank to fill

Here's another way to look at a weight-loss plateau: Think of your body as you would a vehicle. To lose weight, you have to cut back on calories or increase your physical activity so that you burn more calories. Doing both is ideal. Over time, as you lose weight, your body doesn't need as many calories to function because there's less of you.

You can compare the energy your body needs to the fuel in your vehicle. A large SUV needs more fuel to fill its tank than a compact car does. As you lose weight, your vehicle (in this case, your body) needs less fuel — fewer calories — to make it operate. That means you'll need to adjust if you want to lose more weight. To break through a plateau, you'll need to tip the energy balance by cutting back more on calories or burning more calories by increasing your exercise. This could be as easy as skipping second helpings at dinner or taking the stairs instead of the elevator as often as you can. Small changes really do add up.