“Where do I even start?” is the question that crosses many people’s minds looking to make a healthy diet change. Nutrition is a growing, dynamic field with much left to explore. It is also a discipline that is often manipulated by the media. Certain diets are often advocated over others as being the key to longevity and optimal health. Whenever asked this question, I always direct people to the basics of nutrition: how food provides the energy and building materials we need to run marathons, maintain a youthful complexion and build a strong body that is healthy and resilient.
It all starts with energy
Food provides us calories, which gives us energy. The body makes use of energy from three macronutrients in our diet. Carbohydrates, proteins and fat lock in chemical bonds within food, which are released when food is metabolized in our digestive tract. This energy must be supplied regularly for us to meet our needs for survival.
How much energy you need is dependent on a variety of factors including age, gender, weight, height, physical activity and health status. The Mifflin St- Jeor is one of the most accurate predictive equations for estimating a healthy individual’s daily energy needs. This equation will determine your basal metabolic rate (BMR), which is the amount of energy you expend in a day at rest. You then multiply this number by an activity factor, which is a number between 1.2 to 1.9- the more active you are, the higher the number you use. It is important to know that nutrition is not an exact science and that this is simply an estimate, albeit a reliable one based on peer-reviewed research.
How to determine your individual estimated daily energy needs:
- Enter your weight, height and age into the following equation to determine your basal metabolic rate (BMR):
Men BMR= (10 x weight in kilograms) + (6.25 x height in centimeters) - (5 x age in years) + 5
Women BMR= (10 x weight in kilograms) + (6.25 x height in centimeters) - (5 x age in years) – 161
- Take this number and multiply it by a number between 1.2-1.9 depending on your activity level (a higher number means you are more active) to determine how many calories you need in a day.
- If you are looking to lose weight, you want to be eating in a calorie deficit of a few hundred calories of this number. If you are looking to gain weight, you will want to do the opposite.
Food to energy: macronutrients
Macronutrients are nutrients that provide our body energy. Unlike micronutrients, they are needed in large quantities in an appropriate ratio to promote optimal health.
Carbohydrates are our major source of energy in the diet and should compromise about 45-65% of our total daily calories. This macronutrient breaks down to glucose, which is our cell’s preferred energy source. Certain carbohydrates boast fiber, which supports our body by helping to keep us regular and binding cholesterol to decrease its absorption in the body- therefore providing heart health benefit.
Sources: dairy, starchy vegetables, whole grains, beans, fruit, nuts and seeds, vegetables
Dietary fat is essential for our cell membranes, mediating cell signaling, digestion, absorption and transport of our fat-soluble vitamins. Some fats are “healthy” and some should be limited or eliminated. Omega-3 fatty acids found in fatty fish are considered essential since we cannot make them ourselves and therefore must obtain from food. Omega-6 fatty acids are also essential but are much easier to obtain from food. The optimal omega-6 to omega-3 ratio is about 1:1. Saturated fats and trans fats both raise our LDL cholesterol linked to increased risk of coronary artery disease. When it comes to dietary fats, aim for 20-35% of your total caloric intake. Avoid trans fats entirely and limit saturated fat intake to about 6% of your daily calories.
Sources: seeds, nuts, olives, avocado, olive oil, fatty fish, edamame, peanut butter
Protein plays several key roles in the body including being a component of enzymes and hormones. Protein is made up of building blocks called amino acids. Some are nonessential and some are essential- meaning they cannot be made by humans and therefore need to be obtained from food. Animal foods offer a complete spectrum of amino acids and are considered complete proteins while plant-based foods are typically incomplete with some exceptions like quinoa and hemp seeds. How much protein we need in a day is based on our body weight and activity level. Healthy adults need 0.8 grams per 1 kilogram of body weight.
Sources: Greek yogurt, quinoa, chicken, grains and legumes, salmon, edamame, hemp seeds, eggs
Micronutrients: small but mighty
Though micronutrients are vitamins and minerals required by the body in small amounts, they are just as vital to our health and wellbeing as macronutrients and must be derived from the diet. Deficiencies can manifest in a multitude of ways- some more apparent than others. I’ve broken down five important micronutrients to be wary of and have highlighted the most quality foods that boost them.
Vitamin A: Vision, immunity and reproductive health are intimately linked to this important fat-soluble vitamin. It is important to note that not all vitamin-A containing foods are the same. Animal foods provide the active form of vitamin A which our body can readily use while plant-based foods like sweet potatoes, provide its precursor carotenoids that will require conversion in the body. The good news is that these carotenoids play their own unique, powerful role- particularly as an antioxidant and anti-inflammatory agent.
Sources: eggs, cheese, spinach, sweet potato, winter squash, kale, grass-fed butter, shrimp
Vitamin D: We can thank the sun for being our primary source of vitamin D. Just ten to fifteen minutes, two to three times per week of skin exposure to the sun is enough to make adequate amounts in the body. It is difficult to get sufficient amounts of vitamin D from diet alone so it is important to be wary during those colder winter months when going outside is not as feasible. This nutrient is intimately linked to calcium absorption and thus maintaining bone health and integrity.
Sources: salmon, egg yolk, fortified milk and yogurt, tuna, sardines, oysters
Calcium: As the most abundant mineral in the body, calcium is needed for more than just bone health. This mineral is involved in muscle contraction, hormone secretion, nerve signal transmission and heartbeat regulation. Our bones are a dynamic tissue- constantly breaking down and rebuilding through a process called remodeling. When our diet is low in calcium, calcium from our bone tissue is withdrawn which can lead to weakening of bones and can increase our risk of developing skeletal disorders.
Sources: collard greens, kale, yogurt, sardines, tahini, white beans, black-eyed peas, cheese
Iron: Fatigue, headaches and brittle nails are three ways that iron deficiency can manifest which is one of the most prevalent deficiencies worldwide. Obtaining enough iron is critical for maintaining energy levels, immune function and cognitive health. Iron from animal proteins like meat and fish is most readily absorbed but vitamin C- containing foods can aid bioavailability of iron from plant-based foods.
Sources: oysters, olives, mussels, lentils, spinach, chickpeas, pumpkin seeds, dark chocolate
Iodine: Thyroid health and iodine go hand in hand. The thyroid gland helps regulate metabolism- our body’s ability to break down food and convert it to energy. Too much or too little can slow down the production of hormones, thus maintaining its balance is key. Sea vegetables and fish tend to be naturally rich sources. It is important to note that the amount can vary in most foods depending on the soil, season and harvesting practices.
Sources: eggs, yogurt, strawberries, shrimp, cod, nori, kelp, watercress
Overwhelm is a common feeling when it comes to making healthier dietary choices in a field that is constantly growing and changing. Each day is a chance to make a healthy choice that will benefit and support your body. Instead of overhauling your diet completely overnight, I advocate small changes over time, which will eventually add up to making you look and feel your best. Knowing the basics of good nutrition will give you the tools you need to make those positive changes.