The Best Protein Bars to Lose Weight

Keeping a protein bar on hand can help you avoid temptations when hunger strikes. However, you must choose wisely. Some protein bars are high in sugar and calories, which can hinder your weight loss goals. The best options for weight loss are low-sugar protein bars made with whole food ingredients.

First things first: Protein bars are a nutritional "supplement." They are not meant to be consumed in the place of real, whole foods, but rather to augment an already adequate, balanced diet. But in a pinch, they can help you meet your daily protein goals when you can't get there with whole foods.

Increasing your protein intake while trying to lose weight has proven benefits. Protein increases satiety, which can help you eat less and cut calories. It does this by generating both sensory and cognitive signals to the brain that you are full and satisfied, according to an article published in Trends in Food Science & Technology in February 2015.

Extra protein can also help you maintain muscle mass while dieting. When you're in a calorie deficit, your body doesn't just break down fat. In fact, in the early stages of calorie restriction, your body uses only a little bit of fat for energy. The rest comes from stored carbohydrate and protein, according to a review in the Journal of the Academy of Nutrition and Dietetics in March 2014. Maintaining muscle mass is crucial for weight loss, as lean muscle increases your resting metabolic rate, or the amount of calories your body burns while at rest.

You may also decide to use meal-replacement bars for weight loss. Eating a protein bar instead of a whole meal can help you cut calories to create the energy deficit needed for fat loss. While this is OK short term, it's not a nutritionally safe practice long term.

Read more: 14 Protein-Packed Breakfasts to Power You Through the Morning

The benefits of extra protein from protein bars depend on the bar itself. Many protein bars on the market are marginally better for you than a candy bar — really.

Look at the nutrition label or ingredients list on some of the bars on the shelves in your local supermarket. A protein bar from one well-known brand contains 21 grams of sugar — almost the same amount found in a similar-sized candy bar. Where does that sugar come from? The second, third and fourth ingredients on the label: beet syrup, brown rice syrup and cane syrup.

Don't let "beets" and "brown rice" fool you. When the sugars from fruits and grains are concentrated and used as sweeteners, they are no better for you than white sugar. They add calories but few or no nutrients to a food, and they have the same effect on your blood glucose levels as sugar.

Sugar is the single-most detrimental "food" for weight loss. According to a review published in Open Heart in August 2016, added sugars promote obesity by causing insulin resistance, which decreases the cells' ability to use glucose for energy and impairs the oxidation of fatty acids for energy. Elevated insulin resistance also increases energy needs.

Added sugars can also be addictive, encouraging the craving for more sugary foods. In fact, according to a study published in PLOS One in February 2015, processed, sugary foods have similar characteristics to drugs of abuse and can cause addictive-like eating behaviors.

Look for protein bars for weight loss with no, or very low, amounts of added sugar. Many food labels now make the distinction between naturally occurring sugars and added sugars. Ideally, look for bars with less than 2 grams of added sugar.

You can also check the ingredients label, but that can be trickier. According to the University of California San Francisco, sugar can appear on ingredients labels in over 61 ways. In addition to brown rice syrup and beet syrup, you may also see:

• Barley malt
• Dextrose
• Maltose
• Date syrup
• Brown sugar
• Corn syrup
• Honey
• Invert sugar
• Lactose
• Malt syrup
• Maltose
• Maple syrup
• Molasses
• Fruit nectars
• Agave
• Raw sugar
• Sucrose

If you see any of these on a label, put the bar back on the shelf. That doesn't mean you have to eat a bar that's bland. Bars that provide natural sweetness from whole fruits, such as dates are OK (in moderation) because they also contain fiber and extra nutrients found in these whole fruits. They have a higher nutrient density, which means the ratio of nutrients to calories is favorable.

You can also look for bars sweetened with stevia or sugar alcohols like xylitol and erythritol. These are calorie-free sweeteners derived from plants that have no effect on blood sugar. They are often found in low-carb protein bars because they can be subtracted from the total carbohydrate count for a lower net carb content.

Just keep in mind that, just because natural sweeteners are calorie-free, it's not a good idea to overdo it. First of all, some people experience digestive distress when they consume too much sugar alcohol. Second, satisfying your sweet tooth with sugar alcohols may not be doing you any favors in the long run. According to the Harvard T.H. Chan School of Public Health, calorie-free sweeteners may cause you to crave more sweet foods and drinks.

Although those chocolate-covered protein bars with caramel are delicious, they are not only high in sugar, but also fat. While some fats are healthy for you, other types aren't. Too much saturated fat raises your bad cholesterol, which increases your risk of heart disease and stroke. Registered dietitian Toni Havala recommends looking for bars with less than 3 grams of saturated fat.

Poly- and monounsaturated fats from nuts and seeds are good-for-you fats, that, in moderation, can improve heart health. Just keep in mind that all fats have 9 calories per gram, as opposed to 4 calories per gram for carbs and protein, which can drive the calorie content up.

While stevia and sugar alcohols are fine for most people, artificial sweeteners are not. According to Havala, artificial sweeteners have been linked to obesity, Type 2 diabetes, heart disease and cancer. Artificial sweeteners include saccharin, acesulfame potassium, aspartame, and sucralose.

The best protein bars for weight loss contain primarily whole food ingredients. Avoid bars with lots of ingredients you've never heard of or can't pronounce.

Read more: 7 Popular Protein Myths Totally Busted by Science

The truth is that most people, except elite athletes who engage in high-volume training routines, can get all the protein they need — even for weight loss — without protein bars. The only true benefit of protein bars is convenience. You can put them in your purse, your desk drawer or your glove compartment for a quick, high-protein snack when you need it. If this keeps you from grabbing a donut in the break room or pulling into the drive through — mission accomplished.

But with a little additional planning, you can pack low-calorie, high-protein whole-food snacks for home or on the go. Some examples include:

• Turkey roll-ups stuffed with cheese and vegetables
• Hard-boiled eggs
• Greek yogurt parfait with berries and nuts
• Edamame

And, with slightly more prep work, you can make your own protein bars with simple ingredients like almonds, dates, cashews, chia seeds, pumpkin seeds and raw cacao powder.