Plateaus are very common, so don't get discouraged! We have plenty of strategies to help you get over a weight loss plateau. And, of course, keep in mind that sometimes you just have to wait them out.
Weight loss is rarely linear, and if you haven't been stuck for a very long time, your weight may continue to decrease. However, if you have plateaued for a while, it might be time to make some changes.
As you lose weight, your body starts to require fewer calories. This is why it becomes more difficult to lose weight as you get leaner. Sometimes, you just need to make small changes in your calorie balance to get back at it. Any weight loss you achieve will come from being in a calorie deficit – this means consuming slightly fewer calories than your body needs to maintain a stable weight. If you've lost weight already, your body may require fewer calories than before to maintain a stable weight. You want to make small changes by either with removing a few calories from your diet, adding to your physical activity, or a combination of both. Even if you are eating a very healthy diet, it's easy to consume too many calories which can inhibit weight loss.
If you are currently maintaining your weight, it means you are in a calorie maintenance. You will want try subtracting calories by about 200-500 (between diet and exercise) from your daily total and continue to monitor.
Counting calories can be a great strategy to help get over your plateau. It is significantly easier to modify your food intake and exercise if you know how many calories you are eating and what foods are contributing these calories. You don't have to keep track of your caloric intake forever, but it may be helpful to give it a shot until you develop an intuition for your calorie balance.
Mobile apps like MyFitnessPal can help you track all of your food and tell you how many calories you are eating. From there, as long as your current calories aren't too low, you can simply change a few food items to get into your calorie deficit range. If you go this route, you will still want to add your protein powder into your daily calorie total. While your personalized protein powder can help with weight loss, it does contain a small number of calories (since protein as a nutrient has calories).