Not all protein bars are created equal, but if you choose the right type, they can be part of a balanced, reduced-calorie weight loss diet. Protein is helpful for weight loss, and these bars are a quick and portable way to increase your protein intake when you're on the go. They shouldn't comprise your only source of nutrition, however, or be used to replace multiple meals in a day, as they don't have all the necessary nutrients for good health.
If you want to lose weight, you need to cut calories. Simply adding protein bars to what you already eat can backfire, as you could wind up consuming more calories than you did previously and gain weight instead of losing it. The same is true if you choose protein bars that are high in calories. Each pound of weight loss requires a 3,500 calorie deficit, so to lose 1 pound per week, you need to have a deficity of 500 calories a day through diet and/or exercise. Women shouldn't consume fewer than 1,200 calories each day, and men shouldn't eat fewer than 1,800 calories, as it could interfere with metabolism and weight loss results.
Importance of Protein for Weight Loss
Getting plenty of protein in your diet can help you feel full and make it easier to lose weight. According to a review article published in 2015 in The American Journal of Clinical Nutrition, the benefits are most obvious when you get at least 25 to 30 grams of protein in each meal. Spreading your protein intake throughout the day helps you more effectively build muscle compared to eating most of your protein at dinner, according to a study published in The Journal of Nutrition in 2014. The more muscle you build, the higher your metabolism; muscle takes more energy to maintain than fat. For a 1,200-calorie diet that's relatively high in protein, aim for 90 grams of protein, 33 grams of fat and 135 grams of carbohydrates per day, and for an 1,800-calorie diet, aim for 135 grams of protein, 50 grams of fat and 202 grams of carbohydrates per day.
What to Look For in a Protein Bar
Choose a protein bar with about 200 calories and at least 10 grams of protein and at least 3 grams of fiber. The most nutritious bars have 10 grams of sugar or less and 2 grams of saturated fat or less. The American Heart Association recommends that women limit their intake of added sugars to no more than about 25 grams per day, and men get no more than about 38 grams per day. If you're just looking for a snack, you may want a bar with fewer calories, however, and these bars should have correspondingly lower amounts of saturated fat and sugar.
Bars that are made mainly with real foods instead of highly processed ingredients are best, and it's better to avoid those that contain partially hydrogenated oil, soy protein and chicory root. Soy protein and chicory root are inexpensive ways for manufacturers to increase protein and fiber, but these aren't high-quality ingredients, and partially hydrogenated oils indicate that the bar contains unhealthy trans fats. It's also better to avoid other highly processed ingredients when possible, such as high fructose corn syrup, artificial sweeteners, fractionated palm kernel oil, and sugar alcohols like mannitol, xylitol, sorbitol and erythritol.
Fitting Protein Bars Into Your Diet
If you're using a protein bar as a meal replacement rather than a snack, the typical 200 calories isn't quite enough calories for a meal, so you'll want to supplement the bar with other nutritious foods, such as a piece of fruit or a serving of vegetables and a single-serving container of low-fat plain yogurt. You could also have a small smoothie along with your protein bar. This should bring the total calorie content of your meal within the 300 to 400 calorie range.
Someone on a 1,200-calorie diet can eat three meals with 300 calories each plus three 100 calorie snacks, while someone on an 1,800-calorie diet could increase the number of calories in each meal to 500 or bump up the snacks to 200 each, making a protein bar a good snack time fit. Your diet should include a mix of fruits, vegetables, whole grains, low-fat dairy, healthy fats and lean protein foods.
Improving Weight Loss Results
Adding exercise to your routine will help you lose more weight and body fat. A study published in Diabetes Care in 2010 found that combining strength training and a reduced-calorie high-protein diet was better for weight loss and improving body composition than a diet lower in protein with resistance training or a high-protein diet without resistance training. Another study, published in The Journal of Nutrition in 2005, found similar results, noting that a high-protein, low-carbohydrate diet combined with cardio five days per week and resistance training two days per week was more effective than a low-protein, high-carbohydrate diet with the same combination of exercise or either diet without the exercise. For weight loss purposes, aim for at least 300 minutes of cardio and two strength-training sessions per week.