Dietary Fat
Understanding fats
Fats are a fundamental yet often misunderstood component of a balanced diet. While there is often a prevailing misconception that fats should be limited or avoided, their role in the health and performance of female athletes is paramount.
The information in this section will delve into the significance of fats in the diet, explore various types of fat, provide recommendations for intake, and offer strategies to effectively incorporate fats into the diet of female athletes.
Fats, scientifically known as lipids, stand alongside carbohydrates and proteins as one of the three macronutrients.
Energy source: Fats are an energy dense nutrient, providing 9 kilocalories (kcal) per gram. This dense energy reserve is particularly valuable for athletes engaged in endurance sports. While carbohydrates serve as the primary energy source, fats also provide energy to the working muscles, especially during low to moderate intensity activities.
Hormone production: Fats are essential for the synthesis of steroid hormones, including the main female reproductive hormones, estrogen and progesterone.
Cellular structure: Fats contribute to the formation of cell membranes through phospholipids and cholesterol. These lipids compose the lipid bilayer in cell membranes, which acts as a semi-permeable barrier, maintaining cell boundaries, regulating substrate transportation, and ensuring proper cell function.
Vitamin absorption: Fat-soluble vitamins such as A, D, E and K, require the presence of dietary fats to be effectively absorbed.
Key roles of fat within the body
One of the primary functions of fat in the body is to store energy for later use. Adipose tissue, also known as body fat, acts as a reservoir of stored energy in the form of triglycerides. Fat can also be stored in the muscle, this is known as intramuscular triglyceride and is an important fuel source during exercise.
Compared to males, females have higher intramuscular triglyceride stores and are more efficient at using them during exercise. The utilization of fat as an energy source during exercise varies based on exercise intensity and duration.
During low to moderate intensity, steady-state activities such as long-distance running or cycling, the body primarily relies on fat oxidation for energy.
Research has shown that during exercise performed in a fasted state, females oxidize more fat to support the energy needs of exercise in comparison to males. By relying on fat as a primary energy source during low to moderate intensity exercise, the body preserves glycogen for high-intensity movements. Slower depletion of muscle glycogen might suggest that female athletes are more fatigue resistant allowing them to perform well in long duration endurance events.
Endurance type training can enhance the body’s capacity to use fat as an energy source, even during higher intensity exercise. Endurance athletes might benefit from undergoing training sessions that are known to increase fat metabolism (i.e., fasted training) during the off-season, where the focus is more on muscle adaptation rather than performance.
Lipid breakdown
The breakdown of lipids is called lipolysis and takes place in the adipose tissue and skeletal muscle.
Types of dietary fats:
Dietary fats (i.e., triglycerides) have a backbone composed of a glycerol molecule and attached to this are three fatty acids.
They are classified based on their chemical composition:
Saturated fats
These fats are typically solid at room temperature and are prevalent in animal products such as butter, full-fat dairy, red meat, and dairy products. Excessive consumption of saturated fats can elevate low density lipoproteins (LDL) which can rise the level of ‘bad’ cholesterol in the blood, therefore limiting saturated fat intake is advised. The American Heart Association Advises 5-6% of total calories to come from saturated fat.
Monounsaturated fats
Liquid at room temperature, these fats are found in foods such as olive oil, avocados, and nuts. They are recognized for their heart-healthy attributes and deserve a prominent place in the diet of athletes.
Polyunsaturated fats
The body requires both omega-3 and omega-6 fatty acids, both of which fall into this category. Sources include fatty fish (e.g., salmon, mackerel), flaxseeds, walnuts, and specific vegetable oils. Omega-3 fatty acids possess anti-inflammatory properties beneficial for post-exercise recovery (see next section).
Trans fats
Artificial trans fats are created when liquid oils are turned into solid fats, and are known to elevate LDLs and cholesterol levels. They are commonly found in processed and fried foods and should be avoided due to their negative health implications.
Omega-3
fatty acids (O3FA)
Benefits
O3FA have been found to have a variety of potential beneficial effects for health and performance, for example, promoting joint health, managing inflammation, protecting brain health and function, and facilitating muscle recovery.
They are therefore of importance for athletes. Despite this, it has been shown that many athletes consume sub-optimal amounts of O3FA within their diet. There are three main types of O3FA which are alpha-linoleic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). It is well-established that EPA and DHA, found in sources such as fish, are more readily absorbed by the body while ALA can be converted to EPA and DHA in the body, but this conversion is not highly efficient.
Research has found that EPA may help to mitigate exercise-induced inflammation, potentially expediting recovery. EPA is also associated with bolstering cardiovascular health, essential for an athlete’s endurance and overall performance.
Sources of O3FA fatty acids:
Fish
Salmon, Mackerel, Tuna, Cod, Sardines
Non-fish alternatives
Olives (oil)
Avocados
Walnuts and
Pumpkin seeds
Soy products: Beans, Milk, Tofu, Edamame, Soybean oil
Vegetable oils: Canola and Linseed
Chia seeds
Supplements
Fish oil
Krill oil
Algae oil
Recommendations
O3FA recommendations
There are no established Recommended Dietary Allowance (RDA) or Daily Value (DV) guidelines for O3FA. Various dietary recommendations exist from different health authorities. For example:
Academy of Nutrition and Dietetics and Dietitians of Canada: 0.5 grams of EPA + DHA daily
European Food Safety Authority: 0.25 grams of EPA + DHA daily
American Heart Association: Two servings of fish each exceeding 3.5 ounces per week
Athletes may require higher O3FA intake in comparison to the general population due to factors such as energy metabolism, training volume and exercise-induced inflammation. In addition, O3FA may be beneficial to athletes during periods of injury or immobilization. Individualized O3FA doses for athletes are recommended because daily requirements vary significantly among athletes, contingent on factors such as gender, body weight, metabolic rate, and training intensity. However, if a standardized dose is required then 1-3 g EPA + DHA may be appropriate. Athletes aiming to enhance their O3FA levels can do so through a combination of dietary sources and supplements.
Considerations
For athletes with specific dietary restrictions, such as vegetarians, seafood allergies, or those who avoid fish, viable alternatives like seaweed, kelp, algae-fortified foods, or algae-based O3FA supplements can be explored.
These supplements come in various forms, including fish oil (typically in ethyl ester form), krill oil (rich in phospholipids and free fatty acids), and algae oil (a plant-based alternative).
Dietary sources of O3FA Fatty Acids
Salmon (cooked)
Serving: 3 ounces (85 g)
EPA: 0.6 g, DHA: 1.2 g
Sardines
Serving: 3 ounces (85 g)
EPA: 0.5 g, DHA: 0.7 g
Tuna
(bluefin) - fresh
Serving: 3 ounces (85 g)
EPA: 0.2 g, DHA: 0.8 g
Salmon - canned
Serving: 3 ounces (85 g)
EPA: 0.3 g, DHA: 0.6 g
Cod liver oil
Serving: 1 teaspoon (5 ml)
EPA: 0.3 g, DHA: 0.5 g
Sea bass (cooked)
Serving: 3 ounces (85 g)
EPA: 0.2 g, DHA: 0.5 g
ALA sources, click each for details
Crab
Serving: 3 ounces (85 g)
EPA: 0.1 g , DHA: 0.1 g
Tuna - canned
in water
Serving: 3 ounces (85 g)
EPA: 0.2 g, DHA: 0.1 g
Chia seeds
Serving: 1 ounce (28 g)
ALA: 5.1 g
Walnuts
Serving: 1 ounce (28 g)
ALA: 2.6 g
Flaxseeds
Serving: 1 tbsp (28 g)
ALA: 2.4 g
Edamame
Serving: ½ cup
ALA: 0.3 g
Refried beans
Serving: ½ cup
ALA: 0.2 g
Canola oil
Serving: 1 tablespoon
(15 ml)
ALA: 1.3 g
The role of fat in hormone production
Fats play a pivotal role in the production of estrogen and progesterone, two hormones critical to female physiology.
These hormones are synthesized from cholesterol, a lipid. Cholesterol acts as the precursor molecule to produce steroid hormones, including estrogen and progesterone. Specialized cells, primarily in the ovaries and adrenal glands, convert cholesterol into these hormones. Adequate dietary fat intake ensures a sufficient supply of cholesterol, facilitating the body’s ability to synthesize estrogen and progesterone.
These hormones, in turn, regulate various aspects of the menstrual cycle, reproductive health, and overall well-being in females, highlighting the essential role of dietary fats in hormonal balance and female physiology.
Recommended fat intake for female athletes
The American Dietetic Association recommends that fats should constitute 20-35% of total daily calorie intake. For female athletes, it is imperative to:
1
- Emphasize sources of healthy fats, including avocados, nuts, seeds, and oily fish
2
- Limit saturated and trans fats commonly found in processed and fried foods
3
- Ensure O3FA are incorporated
into the diet
Incorporating fats into the diet
Female athletes should prioritize healthy fat sources such as avocados, nuts, seeds, and fatty fish while being vigilant about saturated and trans fat intake (see below). Tailoring fat consumption within a personalized nutrition plan designed to meet an athlete’s unique needs can unlock the full potential of fats for female athletes.
Female athletes can seamlessly integrate fats into their diet through various foods and cooking methods:
Drizzle olive oil on salads and vegetables
Include a handful of nuts or seeds as a convenient snack, or use as a topping on meals e.g., salads
Consume oily fish such as salmon as source of both fat and protein
Utilize avocados as a topping for sandwiches or salads, or as an ingredient in smoothies
Elevate the nutritional value of breakfast by incorporating nut butter into oatmeal or pairing it with fruit
Meals and snacks incorporating ‘healthy’ fats
Click through each for menu details and step by step instructions
Crunchy Oat Bars
Method
1. Pre-heat the oven to 350°F/180°C.
2. Line a baking tray with parchment paper. Add the Quaker oats, pumpkin seeds and chopped almonds. Toast for 7-9 min, until lightly golden. Set aside to cool slightly.
3. Combine the toasted oats, almonds and pumpkin seeds with the coconut, millet, and flaxseeds in a large mixing bowl. Stir to combine.
4. In a medium saucepan add the nut butter, honey, and oil and warm over a medium heat using a spoon to combine the ingredients. Simmer until runny and bubbly. Remove from the heat and stir in the vanilla.
5. Pour the almond/peanut butter mixture over the oat mixture. Use a spatula to stir the mixture together until well combined.
6. Transfer to a parchment paper lined container 20 cm x 20 cm and use the spatula to evenly spread the mixture. Lay another sheet of parchment paper over the top, then using another baking tray, press down evenly over the top to condense the mixture into an even layer.
7. Refrigerate for a minimum of 4 hours, then cut into 24 even bars.
Ingredients
2 cups (180 g) Quaker Oats
1 cup (80 g) Coconut (shredded)
1 cup (100 g) Almonds (chopped)
3/4 cup (75 g) Cashews
1/2 cup (100 g) Millet
¼ cup (45 g) Flax seeds
1 cup (250 g) Nut butter
¼ cup (85 g) Honey
¼ cup (45 g) Canola oil
1 tbsp (15 g) Vanilla
Baked Sweet Potatoes with Feta
Method
1. Preheat the oven to 400°F/200°C.
2. Scrub the potato, then wipe it dry and place on a baking tray. Bake for 45-55 min, or until the potato is tender when pierced with a fork (or if in a rush place in the microwave for 4-5 min).
3. Whilst the potato is baking, in a medium frying pan, toss the chopped kale in olive oil, salt, pepper and flaxseeds. Over a medium heat, sauté the kale for approximately 5 min until slightly wilted.
4. Slice the sweet potatoes in half lengthwise. Use a fork to loosen the potato and mix in the kale, parmesan, and walnuts. Crumble the feta on top and return to the oven for 10-12 min to melt the feta.
Ingredients
Serves 1
1 pc (150 g) Sweet potatoes
1 bunch (15 g) Kale or spinach
½ tsp (3 g) Extra virgin olive oil
¼ cup (50 g) Parmesan cheese
1 pinch (2 g) Salt
1 tsp (6 g) Flaxseeds
1/8 cup (15 g) Walnuts chopped
¼ cup (30 g) Feta cheese
½ pc (70 g) Pepper
Peanut Butter Chia Pudding
Method
1. Mix the chia seeds with the milk, stir until well combined.
2. Leave to thicken in the fridge for at least half an hour (ideally overnight).
3. Top with sliced banana and peanut butter.
Ingredients
Serves 1
3 tbsp Chia seeds
½ cup Milk of choice
2 tbsp Peanut butter
1 Banana sliced
Salmon Toast
Method
1. Blend the oats with water, black olives, black pepper, olive oil, cumin and cashews to form a spread. Control the speed of the blender, as well as how long you blend for, to reach your preferred texture of chunky or smooth.
2. Toast the bread slices.
3. Spread the oat blend mixture on top of each slice of toast and garnish with the toppings.
Ingredients
Spread
½ cup (100 g) Water
¼ cup (23 g) Oats (Quaker Old Fashion)
¼ cup (35 g) Black olives
1 pinch Black pepper
½ tsp (3 g) Extra virgin olive oil
1 pinch Cumin
¼ cup (30 g) Cashews
2 slices (20 g) Whole wheat bread
Toppings
2 slices (30 g) Smoked salmon
6 slices (35 g) Cucumber
1 tsp (5 g) Red onions (Chopped)
¼ tsp (1 g) Sesame seeds
1 tsp (2 g) Capers
½ tsp (3 g) Extra virgin olive oil
¼ tsp (1 g) Lime Juice
¼ tsp (1 g) Dill (chopped)
Greek Yogurt Dessert
Method
1. Use the fine side of a cheese grater to make the shaved dark chocolate.
2. Chop the pecans.
3. Put the Greek yogurt into a dessert dish and drizzle with honey and sprinkle with the shaved dark chocolate and chopped pecans and serve!
Ingredients
Serves 1
1 cup (250 g) Plain Greek yogurt
2 tsp (14 g) Honey
1 tsp (5 g) Shaved dark chocolate
(70%+ cocoa)
1 tbsp (10 g) Chopped pecans
(or any nut alternative)
Avocado and Egg Bagel
Method
1. Start by making the guacamole. Deseed the avocado and remove the flesh from the skin, mash this with the back of a fork. Add in the tomatoes and red onion and mix well. Squeeze in the lime juice, mix well. If using, add the cilantro and chilli.
2. Slice bagel in half and toast.
3. Meanwhile crack the egg into a pan of boiling water and cook for 3-4 min until the whites are set.
4. Assemble by spreading the guacamole on the two sides of the bagel. Place the egg on one bagel half and place the other half on top.
Ingredients
Serves 1
1 Seeded bagel
1 Egg
For the guacamole:
1 Avocado
5 Cherry tomatoes, diced
½ Lime (juice)
¼ Red onion, diced
Cilantro and crushed chilli (optional)
Summary
Fats play an important role to support the health and performance of all athletes, including females. They serve as a valuable energy source, contribute to cellular structure, aid hormone production and vitamin absorption, and play a crucial role during exercise.
Omega-3 fatty acids, potentially offer unique benefits, such as improved joint health and muscle recovery, as well as inflammation reduction, which can be advantageous for female athletes. By following recommended fat intake guidelines and incorporating healthy fats into their diets, female athletes can unlock the full potential of these essential nutrients, supporting their overall health, endurance, and athletic success.
Understanding the types of dietary fats and making informed choices can significantly impact an athlete’s health and performance.
Dietary Fat
References
