Toning is another way of describing building muscles, and it requires both diet and exercise. A female body toning diet should focus on decreasing body fat while increasing lean muscle mass — doing these two things in tandem will increase the appearance of muscle definition and a toned body.
Caloric Intake and Weight Loss
An important part of toning is reducing body fat through weight loss, which can be achieved by consuming fewer calories than you burn off. The number of calories your body uses every day is also called total energy expenditure and includes maintaining cellular functions, digestion and physical activity.
The total recommended number of calories a woman should consume every day depends on her age, weight, height, physical activity and other factors. The USDA, in its 2015-2020 Dietary Guidelines for Americans, recommends that adult women eat about 1,600 to 2,400 calories a day.
The lower end of the range is for sedentary adults, while the higher end is for active adults, defined as walking more than three miles per day at 3 to 4 miles per hour. Increased physical activity may require increasing daily caloric intake.
Read more: 20 Best Muscle Building Foods
While calorie restriction can result in weight and fat loss, an August 2015 research review in the International Journal of Obesity showed that the body tends to adapt, and metabolism becomes more efficient. This cutting calories is not a sustainable, long-term strategy for weight loss. Instead, a meal plan for women should focus on building muscle.
Protein and Building Muscles
Protein is an important macronutrient — it's found in muscles, skin, bones, hair and body tissues. Human bodies don't store the essential amino acids that make up protein, so those amino acids must come from food. Because protein is a basic element of muscles, eating protein can help maintain and build female muscle mass.
Numerous studies have directly linked protein and building muscle. A January 2015 study in Sports Medicine showed that protein could help enhance muscle mass and performance in physically active adults. Similarly, a September 2012 review in the Journal of the International Society of Sports Nutrition showed that increasing dietary protein helped increase muscle and strength during resistance training.
In addition, eating protein is important in calorie restriction, because in cases of significant weight loss, the body also loses lean body mass. In an April 2014 article in the International Journal of Sport Nutrition and Exercise Metabolism, researchers found that increasing protein helped maintain muscle mass in athletes who were following a restricted calorie diet.
Read more: 5 Tips for Eating Protein the Right Way
An August 2012 article in the British Journal of Nutrition also showed that protein helps with satiety (i.e., the feeling of being full) and can be instrumental in body weight loss and weight management. This applies to protein-filled snacks as well — a September 2016 study in Advances in Nutrition showed that snacks that are filled with protein can promote satiety and help avoid overconsumption at the next meal.
Meal Plan for Toning
Since protein is vital to building muscles, a meal plan for toning and building muscle in a female should include various sources of protein.
For general health, the USDA Dietary Guidelines for Americans recommends (based on the Institute of Medicine's Macronutrient Dietary References Intake) 0.8 grams of protein per kilogram of body weight; for adult women, that is around 46 grams. The USDA also has a Dietary References Intake Calculator to determine nutrient levels for individuals based on age, height and weight.
However for building and maintaining muscle mass, which would be necessary with a toning diet, the International Society of Sports Nutrition recommends a daily intake of 1.4 to 2.0 grams of protein per kilogram of body weight.
Not all proteins are created equal, however. The USDA makes a distinction between "complete proteins," which contain all nine essential amino acids, and "incomplete proteins," which are deficient in at least one of the amino acids. It is possible to eat different sources of incomplete proteins in order to fulfill all the amino acid requirements.
Animal protein sources: Meat, poultry, fish and eggs are considered complete proteins. However, the entire "protein package" — that is, how much fiber, good and bad fat and sodium a protein has — should be considered. For example, even though a sirloin steak and grilled sockeye salmon both have around 30 grams of protein, the salmon is lower in saturated fat and contains omega-3 fats, which help with heart health.
Red meat is also associated with other health risks. A March 2012 article in the journal Stroke showed a correlation between red meat and the risk of stroke in both men and women. The National Institutes of Health also cautions that eating a diet rich in red meat, compared to one in white meat or plant-based protein, elevates the level of a heart disease-related chemical.
Individuals who eat animal protein should try to limit red meat and eat leaner sources like seafood, eggs and white meats such as chicken or turkey.
Dairy protein sources: Milk, cheese and yogurt are also considered complete proteins. A November 2016 review in Food & Nutrition Research showed that consuming milk and dairy products in your diet can help provide nutrients like calcium and protect against chronic diseases like Type 2 diabetes.
Plant-based protein sources: Plant-based proteins are considered incomplete but can be combined to provide the body with all the essential amino acids. Plant-based proteins also have a lower environment impact as their production has lower greenhouse emissions than the production of animal meats. Good plant-based options include lentils, beans, soybeans, chickpeas, nuts and whole grains such as wheat and quinoa.
Read more: 13 Surprising Vegetarian Sources of Protein
Carbohydrates: In a January 2018 report in Nutrition Today, researchers noted that even though protein is important for active individuals, high-quality carbohydrates such as potatoes are still an essential source of energy for the body. Thus, a toning diet should also incorporate carbohydrates from whole foods, particularly for individuals who engage in physical activity.
Water: Finally, proper hydration is necessary for keeping crucial body functions and maintaining a healthy body weight. Total daily water intake (which includes drinking water but also the water content from foods that are eaten throughout the day) varies by individual, age, gender, activity level and more. The Institute of Medicine of the National Academies recommends that women consume around 91 ounces, or approximately 11 cups, of water daily.
Resistance Training and Toning
Resistance or strength training can help build muscles and improve toning definition through muscle hypertrophy. When you engage in resistance training, either via body weight or external weights, muscle fibers experience trauma. When the muscles repair themselves, they grow in size.
An April 2016 study in the International Journal of Exercise Science, showed that in both men and women, both low and high frequency strength training (i.e., number of times worked out per week) resulted in improvements in lean mass and strength and building back lost muscle tissue that commonly occurs with aging.
Many research studies show that increased protein intake combined with resistance training helps build muscles. An October 2015 article in the Journal of the International Society of Sports Nutrition showed that a high-protein diet, in conjunction with heavy resistance training, improved body composition (for example, a decrease in fat mass and percent body fat).
- International Journal of Obesity: "Physiological Adaptations to Weight Loss and Factors Favouring Weight Regain"
- U.S. Department of Health and Human Services and U.S. Department of Agriculture: "2015-2020 Dietary Guidelines for Americans: Appendix 2. Estimated Calorie Needs per Day, by Age, Sex, and Physical Activity Level"
- Harvard T.H. Chan School of Public Health: "Protein"
- Sports Medicine: "The Effects of Protein Supplements on Muscle Mass, Strength, and Aerobic and Anaerobic Power in Healthy Adults: A Systematic Review"
- Journal of the International Society of Sports Nutrition: "Dietary Protein to Maximize Resistance Training: A Review and Examination of Protein Spread and Change Theories"
- International Journal of Sport Nutrition and Exercise Metabolism: "A Systematic Review of Dietary Protein During Caloric Restriction in Resistance Trained Lean Athletes: A Case for Higher Intakes"
- British Journal of Nutrition: "Dietary Protein - Its Role in Satiety, Energetics, Weight Loss and Health"
- Advances in Nutrition: "Snack Food, Satiety, and Weight"
- The Institute of Medicine: "The Institute of Medicine’s Macronutrient Dietary References Intake"
- U.S. Department of Health and Human Services and U.S. Department of Agriculture: "Dietary Reference Intakes Calculator"
- Stroke: "Dietary Protein Sources and the Risk of Stroke in Men and Women"
- National Institutes of Health: "Eating Red Meat Daily Triples Heart Disease-Related Chemical"
- Food & Nutrition Research: Milk and Dairy Products: Good or Bad for Human Health? An Assessment of the Totality of Scientific Evidence"
- Nutrition Today: "High-Quality Carbohydrates and Physical Performance"
- The Institute of Medicine of the National Academies: "Dietary Reference Intakes: Water, Potassium, Sodium, Chloride, and Sulfate"
- University of New Mexico: "How Do Muscles Grow?"
- International Journal of Exercise Science: "Increasing Lean Mass and Strength: A Comparison of High Frequency Strength Training to Lower Frequency Strength Training"
- Journal of the International Society of Sports Nutrition: "A High Protein Diet (3.4 G/Kg/D) Combined with a Heavy Resistance Training Program Improves Body Composition in Healthy Trained Men and Women: A Follow-Up Investigation"
- Journal of the International Society of Sports Nutrition: "International Society of Sports Nutrition Position Stand: Protein and Exercise"
- U.S. Department of Health and Human Services and U.S. Department of Agriculture: "Dietary Guidelines 2015-2020: Appendix 7. Nutritional Goals for Age-Sex Groups Based on Dietary Reference Intakes and Dietary Guidelines Recommendations"