Research About Meatless Monday and Nutrition

Starting a Meatless Monday practice is the first step toward a more plant-forward diet. Our scientific advisors share how you can make this change in a healthy, satisfying way.

The following information was composed by Diana K. Rice, a Registered Dietitian, with additional writing provided by Becky Ramsing, Senior Program Officer at The Johns Hopkins Center for a Livable Future.

Nutritional FAQ

Do I need to worry about getting enough protein on Meatless Monday?
No. Protein deficiency is very rare, even in full-time vegetarians. As long as you’re eating enough calories to maintain a healthy weight and following the USDA’s Dietary Guidelines or Choose My Plate, you’re almost certain to get enough protein.

Do I need to combine certain foods during meals to ensure protein quality?
No. Although most plant protein sources provide limited amounts of some of the essential amino acids, it isn’t necessary to combine foods to create “complete proteins.” If you eat a variety of foods and follow the USDA Dietary Guidelines, your body will have all the amino acids it needs to make the new proteins your body needs.

Read our Plant Protein Power FAQ for more on plant-based protein.

What about iron or B12?
Going meatless for one day a week will not create iron or B12 deficiencies. Iron is present in many vegetables, beans and grains, and even full-time vegetarians can get enough of these nutrients without meat. People who never consume animal products of any kind (i.e. vegans) may need to supplement with B12.

VITAMINS AND MINERALS: Both animal and plant sources of protein have a variety of important minerals and vitamins. B12 is the only vitamin available solely in animal foods. If an individual occasionally eats meat, eggs or dairy, they will obtain sufficient B12. A strict vegan may need a B12 supplement.

IRON: Animal proteins contain heme iron, which is more readily utilized by the body. Plant sources have non-heme iron, which is less available for use. However, eating foods that contain vitamin C or other heme-containing foods together with the plant protein enhances the iron’s availability. For example, a bowl of beans with chopped red peppers or tofu with broccoli.

For more on nutritional considerations of a vegetarian or vegan lifestyle, visit the Vegetarian Resource Group.

Is a meatless diet automatically healthier?
No. Eliminating meat doesn’t automatically make your diet healthier. It’s still important to eat the right balance of healthy foods and to limit your intake of unhealthy foods. Eat less sugar, refined flours and processed foods. And eat plenty of vegetables, whole grains, fruit and other plant-based proteins.

Will going without meat cause me to lose weight?
Not necessarily. Depending on how they’re prepared, plant protein sources like beans and legumes can be lower in fat and calories and higher in fiber. People who eat less meat tend to have a lower body weight. However, meatless diets aren’t necessarily lower in calories. Follow the USDA Dietary Guidelines or Choose My Plate to manage your calorie intake.

Should I avoid exercising if I’m not eating meat?
There’s no need to avoid exercise with Meatless Monday. A healthy meatless diet will provide more than enough energy, protein and other nutrients to fuel all of your usual activities, including your workouts.

What if I’m on a low-carb diet?
Most beans and legumes are relatively high in complex carbohydrates (meat contains no carbohydrates). If you’re restricting carbohydrates, you may want to choose nuts and seeds, eggs and low-fat dairy products as your primary protein foods. Green vegetables, which are low in carbohydrates, can also be an important source of protein. Keep in mind that whole grains, vegetables and legumes are complex carbohydrates that provide healthy fiber and are not the same as the simple carbohydrates found in sugar and refined flour.

What about eating out?
As more and more people are choosing meatless lifestyles, it’s getting easier to find meatless options on restaurant menus. Most restaurants now offer at least one vegetarian entrée. Ethnic foods, such as Indian, Asian and Mexican restaurants usually have many tasty, meatless options.

Should I cut fats completely out of my diet?
No. While Americans eat too much dietary fat in general, fat remains an important nutrient. There are, however, fats that are beneficial to health and others that aren’t. According to the CDC Healthy People 2010 Report, researchers have found that diets low in saturated fatty acids and cholesterol are associated with low risk and rates of coronary heart disease. Substituting foods high in these fats for healthier fats can help lower health risks.

The primary sources of saturated fats are meats and high fat dairy products. Monounsaturated and polyunsaturated fatty acids do not raise blood cholesterol and are considered healthier fats. Foods high in monounsaturated and polyunsaturated fat include olive, canola and sesame oils, nuts and nut butters, seeds, flaxseed, and avocados.


Got questions about Soy? Read our Soy FAQ.

For more tips and resources to join the Meatless Monday movement, visit  the Meatless Monday Resources page.

For more information about using a Monday cue to support healthy behavior, visit The Monday Campaigns Research page .