Nutrition for Active Women: Macro & Micronutrient Essentials

Proper nutrition as a part of a healthy eating plan is essential for physical activity and health. As a fitness professional, this can be a challenging topic not only because of a personal trainer's scope of practice but also because nutrition needs vary from person to person. Although it is important to remember that every individual has different needs, there are some general guidelines for certain populations. For example, women's nutritional needs are different from men's. The nutritional needs of active individuals are different than those that are sedentary. And, those needs can change throughout the aging process.

Caloric Needs for Active Women

Generally speaking, if a client's goal is weight loss, they should consume fewer calories than they burn. If the goal is weight gain, they should consume more calories than they burn. Women who exercise need to eat sufficient calories to provide their bodies with the proper energy for activity and recovery. But, there needs to be a healthy balance so they aren't consuming an excess of calories that could contribute to extra weight (unless weight gain is the goal). However, energy intake needs for an active female client can vary quite a bit. Age, physical activity level, metabolism, weight, and muscle mass are all factors when considering caloric needs for women.

The US Dietary Guidelines 2015-2020 recommends somewhere between 2,000 and 2,400 calories per day for physically active women 18+. However, this recommendation defines active as "walking more than 3 miles per day at 3 to 4 miles per hour, in addition to the activities of independent living." So, for weekend warriors, athletes, or women that exercise more than walking three miles per day, calorie intake may need to be much higher (1).

Some research aligns with the recommendations above. The recommended energy intake for a normal active individual (an individual that participate in exercise 30-40 minutes per day, three times per week) is 35 kilocalories per kilogram of body weight per day (kcals/kg/day), which would equate to almost 2,400 calories for a 150-pound woman. However, as activity level and body weight increase, caloric needs can be anywhere from 50-80+ kcals/kg/day (2).

Although many factors contribute to an individual's energy intake needs, there are equations and tools available to help calculate an estimate of caloric needs for an individual. One of the more common equations is the Harris-Benedict Equation. The calculation utilizes an individual's basal metabolic rate (BMR) and multiplies it by their physical activity level to calculate their energy needs.

Macronutrient Needs for Active Women

The number of calories is important but the quality of those calories is just as important for performance, health, and weight. There are three macronutrients to consider as a part of a healthy eating plan: carbohydrates (carbs), protein, and fats. Women need a combination of all three for exercise and healthy body function. But, similar to caloric needs, macronutrient needs vary by individual.

Carbohydrates

Carbs are typically the main source of energy for the body. Individual carbohydrate needs can vary by age, physical activity level, and body size. Some research suggests that a healthy eating plan for a normal active individual (participates in 30-40 minutes of physical activity three times a week) should consist of 3-5 grams per kilogram of body weight per day (g/kg/day) (2). However, physical activity levels can vary substantially, so, additional research suggests that carbohydrate needs can be anywhere between 3-12 g/kg/day (3).

Keep in mind, time of consumption (related to exercise), dietary fiber, and type of carbohydrate are important as well. Consumption of high-quality carbohydrates that are nutrient-dense is ideal. However, both simple and complex carbs can be valuable for active individuals (4).

Good sources of dietary carbohydrates:

• Quinoa

• Oats

• Sweet potatoes

• Whole grains

Protein

The amino acids in high-quality plant protein and/or animal protein is needed to build, maintain, and repair muscle mass. Protein intake is also essential for weight management, cellular structure, and connective tissue. Research suggests that a healthy eating plan for a normal active individual (participates in 30-40 minutes of physical activity three times a week) should consist of 0.81 g/kg/day of protein. However, for more active individuals, protein needs may be between 1.2-2 g/kg/day with some clients requiring even more protein than that (2).

Good sources of dietary protein:

• Fish

• Lean meats

• Lentils

• Eggs

Fat

Research suggests that fat intake for a normal active individual (participates in 30-40 minutes of activity three times a week) should consist of 0.5-1.5 g/kg/day or about 25-35% of the diet (2). This is in alignment with the US Dietary Guidelines recommendation for the average woman. So, the daily intake recommendation for fat isn't much greater, if any different at all, for active women than it is for non-active women.

The two considerations active women will want to keep in mind with regard to their daily fat intake are to focus on limiting excess fat consumption and make an effort to consume healthy fats.

Good sources of dietary fat:

• Nuts

• Olive oil

• Avocados

Micronutrient Needs for Active Women

There are many different micronutrients (vitamins and minerals) the human body needs. They are essentials for hundreds of processes and chemical reactions within the body. Similar to caloric intake and macronutrient needs, individual micronutrient needs vary for each individual as well. Although several factors influence a client's dietary needs, there are a few nutrients that are especially important for the women that exercise. Calcium, vitamin D, and iron are at the top of the list.

Calcium

Calcium plays a significant role in bone health and the muscle contraction process which makes calcium an incredibly important nutrient for active women. Inadequate calcium intake can result in compromised bone density and bone health. When calcium intake is low, the body can pull calcium from the bones which can lead to issues with osteoporosis and bone fractures. The adequate intake of calcium for women over 19 is 1,000 milligrams per day (mg/day) but increases to 1,2000 mg/day after age 51 (5).

Good sources of dietary calcium:

• Milk

• Cheese

• Yogurt

Vitamin D

The role of vitamin D is to help with the absorption of calcium and phosphorus in the body. Vitamin D's importance, in regard to exercise, is primarily its significance in the calcium absorption process. The adequate intake of vitamin D for individuals over the age of 18 is 5 mg/day. It increases to 10 mg/day at age 51 and then 15 mg/day at age 71. Vitamin D is mostly absorbed through access to sunlight. However, there are some foods that contain vitamin D (6).

Good sources of dietary vitamin D:

• Eggs

• Fatty fish

• Food fortified with vitamin D

Iron

Iron is involved in a handful of different processes within the body. But, it is most well-known for the role it plays in transporting oxygen in the body. This makes iron critical for exercise and active women. Most women tend to lose iron every month because of menstruation. If they don't replace it, iron deficiency can become a concern. The recommended daily allowance (RDA) for women over the age of 19 is 18 mg/day. The RDA for iron drops to 8 mg/day after age 51. However, research suggests that women that partake in regular intense physical activity may require 30-70% more (7).

Good source of dietary iron:

• Red meat

• Liver

• Spinach

• Food fortified with iron

With all nutrition, balance is key. More isn't necessarily better. A mixture of protein, fat, and carbs in alignment with calorie needs is important for all women but especially those that exercise. And, it's important for women who exercise to make sure they are getting important micronutrients like iron, calcium, and vitamin D. Although the nutritional needs of each client will vary, you can help guide your female clients to the appropriate recommendations so they can make the proper nutrition choices for their physical activity level and body.

Are you interested in learning more about nutrition? Check out ISSA's Nutrition Certification and learn more!

References

1. U.S. Department of Health and Human Services and U.S. Department of Agriculture. 2015-2020 Dietary Guidelines for Americans. 8th Edition. December 2015. Available at https://health.gov/dietaryguidelines/2015/guidelines/.

2. Pramuková B, Szabadosová V, Soltésová A. "Current knowledge about sports nutrition." Australas Med J. 2011;4(3):107-110. doi:10.4066/AMJ.2011.520

3. Thomas, D.T., K.A. Erdman, and L.M. Burke (2016). "Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and athletic performance." J. Acad. Nutr. Dietet. 116: 501-528.

4. Kanter M. "High-Quality Carbohydrates and Physical Performance: Expert Panel Report." Nutr Today. 2018;53(1):35-39. doi:10.1097/NT.0000000000000238

5. "Calcium ." Institute of Medicine. 2006. Dietary Reference Intakes: The Essential Guide to Nutrient Requirements. Washington, DC: The National Academies Press. doi: 10.17226/11537.

6. "Vitamin D ." Institute of Medicine. 2006. Dietary Reference Intakes: The Essential Guide to Nutrient Requirements. Washington, DC: The National Academies Press. doi: 10.17226/11537.

7. "Iron ." Institute of Medicine. 2006. Dietary Reference Intakes: The Essential Guide to Nutrient Requirements. Washington, DC: The National Academies Press. doi: 10.17226/11537.