Macronutrients

1. Introduction to Macronutrients

• Definition of Macronutrients

Macronutrients are the nutrients our bodies require in large amounts to function properly. The three main macronutrients are:

• Carbohydrates: The main source of energy for the body. They get broken down into glucose which the cells use for fuel. Good sources include whole grains, fruits, vegetables, beans and dairy.
• Proteins: Provide amino acids that build and repair tissues like muscle. Also play roles in immune function, hormone regulation, and nutrient transportation. Found in foods like meats, eggs, fish, poultry, nuts, seeds and legumes.
• Fats: A key energy source and aids absorption of some vitamins. <mark>Essential fatty acids</mark> must come from food since the body cannot make them. Healthy fats like olive oil and avocados should make up 20-35% of daily calories.

Some key points:

• Adults need 225-325 grams of carbs daily for energy, brain function and muscle movement
• The RDA for protein is <mark>0.8 grams per kilogram of body weight</mark> per day
• Balance all three macronutrients by eating a variety of whole foods for good health

Their effects are synergistic so focus on the dietary ratio rather than amounts alone.

Importance of Macronutrients in Nutrition

Consuming a balance of macronutrients – carbohydrates, proteins and fats – is vital for maintaining good health and function. Though the body requires them in smaller doses, micronutrients get more attention. However, macronutrients comprise the bulk of food intake and play crucial roles. Understanding what each does and why we need it is key to healthy eating.

• Carbohydrates: Provide glucose that cells rely on for energy and fuel brain activity. They fuel working muscles during exercise allowing longer, more intense workout sessions. The digestive system breaks carbohydrates from whole grains, fruits, vegetables, beans and dairy foods into glucose. Adults need between 225-325 carbohydrate grams daily for energy, cognitive function and performance.
• Proteins: Supply amino acids that build and repair tissues including muscle, skin, bones and organs. Unlike carbs and fat, the body does not store protein efficiently. Therefore it needs a steady protein supply from high-quality sources like meat, poultry, seafood, eggs, legumes, nuts and seeds to function properly. The Recommended Daily Allowance is <mark>0.8 grams of protein per kilogram of body weight</mark> to spare muscle breakdown. Active individuals may require more.
• Fats: Get blamed for weight gain but healthy types like monounsaturated and polyunsaturated fats protect against inflammation, heart disease and other conditions. They provide insulation to preserve body heat and cushion organs. Fats improve absorption of fat-soluble vitamins A, D, E and K too.

While micronutrients lend crucial support, macronutrients do the heavy lifting. Getting sufficient protein, healthy fats and complex carbs from whole foods ensures energy for cells, fuels workout performance and keeps organs and tissues functioning optimally. Each plays integrally in maintaining health.

Carbohydrates: The Energy Providers

Overview of Carbohydrates

Carbohydrates are vital macronutrients that provide the body with glucose for energy. However, not all carbs are equal when it comes to nutritional value and health impact. The three main types of carbohydrates are:

• Sugars: Simple carbohydrates like glucose and fructose that digest and absorb quickly. Found naturally in fruits, dairy and vegetables. Also added to sodas, desserts and candies. Provide fast but short-lived energy boosts.
• Starches: Long chains of glucose known as complex carbs taking longer to break down. Examples are starchy vegetables like potatoes, whole grains like brown rice and breads. Provide longer lasting energy for cells.
• Fiber: Indigestible carbs that pass through the body undigested. Soluble fiber dissolves into a gel, helping reduce blood cholesterol and glucose levels. Insoluble fiber adds bulk to promote regularity. Found in fruits, vegetables, whole grains, nuts and legumes. Critical for gut health.

The healthiest carbohydrate sources come from whole, nutrient-dense foods like fruits, beans, 100% whole grains and starchy vegetables which provide vitamins, minerals and fiber. Refined grains like white bread and white rice as well as added sugars deliver carbs with less nutritional value.

Aim to get complex carbohydrates from starches and naturally occurring sugars plus plenty of high-fiber carbs while limiting added sugars and refined grains. The quality of carbohydrates matters greatly for energy, weight control and reducing disease risks.

Carbohydrates are an essential macronutrient that serve several important roles in the human body including:

• Providing Energy – The primary role of carbs is to supply the body and brain with energy. All digestible carbs get broken down into glucose which directly fuels cell function. Carbs are the preferred energy source for muscle contraction during exercise.
• Preventing Protein Breakdown – Consuming adequate carbs spares the breakdown of proteins from muscles and tissues for energy needs. This allows dietary protein to do its main job – for growth and repair.
• Supporting Brain Function – A steady glucose supply is crucial for optimal brain activity. Carbs aid the synthesis of important neurotransmitters that regulate cognition, mood and nervous system function.
• Boosting Fiber Intake – Fiber-rich complex carbs feeds good gut bacteria and promotes bowel regularity. Soluble fiber may help regulate cholesterol and blood sugar as well.
• Providing Essential Vitamins/Minerals – Whole food carb sources supply important vitamins, minerals, phytonutrients vital for health that refined grains and sugars lack.
• Sparing Fat Metabolism – Eating sufficient carbs decreases the need to use stored body fat or dietary fats for energy resulting in conserved body fat.

Replenishing glycogen stores after exercise and fueling everyday activity would not be possible without adequate carbohydrates from wholesome foods like fruits, vegetables and whole grains. High-fiber carbs deliver maximum nutritional value for good health.

• Sources of Carbohydrates

Carbohydrates are found in a range of nutritious foods. The healthiest sources provide fiber, vitamins and minerals in addition to carbs. Main sources include:

• Fruits: Fruits like apples, bananas, berries and citrus contain natural sugars like fructose and sucrose. Also provide fiber, antioxidants and nutrients.
• Starchy Vegetables: Potatoes, corn, peas, squash and root vegetables contain starch made of long glucose chains. Also rich in fiber, minerals like potassium.
• Whole Grains: Oats, brown rice, 100% whole grain bread, farro and quinoa provide protein and abundant fiber. Refined grains lose nutritional value in processing.
• Legumes: Beans, lentils, chickpeas and green peas are high in slowly-digested carbs, fiber, lean protein, iron, magnesium. Help lower cholesterol.
• Dairy: Milk contains the sugar lactose plus protein, calcium, vitamin D, phosphorus. Low-fat versions minimize saturated fats. Yogurt has benefits of probiotics.
• Nuts and Seeds: Almonds, pistachios, pumpkin seeds- good source of monounsaturated fats, fiber, vitamin E, magnesium. Help reduce heart disease risks.
• Added Sugars: Sugar, high fructose corn syrup, honey, maple syrup provide carbs but lack nutritional value if over-consumed and may negatively impact health.

Choose complex, fiber-rich carbs from whole fruits, vegetables, nuts rather than refined flour or added sugars for maximal nutrition and health benefits.

Recommended Intake of Carbohydrates

Carbohydrates should comprise 45-65% of total daily calorie intake according to dietary guidelines. However, the optimal amount varies based on age, gender, activity levels and health goals.

Minimum Intake

The minimum recommended limit for carb intake is 130 grams per day. Eating less may cause nutritional deficiencies over time and make it difficult to meet daily calorie needs. Very low carb diets can negatively impact hormone regulation, gut health and mood in some individuals as well.

General Recommendations

The Dietary Guidelines for Americans currently recommend the following for adequate carb levels:

• Women: 135g/day
• Men: 180g/day
• Pregnant women: 175g/day
• Breastfeeding women: 210g/day

Athletes/Active Individuals

Those who engage in moderate to high intensity exercise require more carbs – minimally 240-300g daily up to 600-800g. Consuming adequate carbs before and after training supports muscle performance, restores glycogen and aids workout recovery.

Low Carb Diets

Deficientlow-carb diets providing less than 120g daily may provide therapeutic benefits for some health conditions, but eliminating entire food groups increases thek for deficiencies without medical guidance.

In general, consuming the majority of daily calories from wholesome carbohydrate sources while minimizing added sugars and limiting refined grains can maximize energy, health and reduce disease risks for most healthy individuals. Needs are always individualized.

Proteins: Building Blocks of Life

Overview of Proteins

Proteins are one of the three macronutrients that are essential to human health. Here is a brief overview:

What Are Proteins?

Proteins are large, complex molecules composed of chains of amino acids – the building blocks of life. The human body uses 20 different amino acids to construct tens of thousands of different proteins.

Functions of Protein

• Growth & development – proteins build, maintain and repair body tissues like muscle, organs, skin, bones
• Enzymes – act as specialized catalysts for essential chemical reactions
• Hormones – regulate appetite, metabolism, reproduction, sleep cycles, tissue function
• Immunity – antibodies protect against foreign pathogens and infections
• Transportation & storage – proteins carry oxygen, lipids, and nutrients in blood and lymphatic system

Dietary Sources

Complete proteins with all essential amino acids come from animal-based foods:

• Meat: chicken, beef, pork
• Dairy: milk, cheese, yogurt
• Eggs
• Fish: salmon, tuna

Plant proteins like nuts, grains and legumes lack 1 or 2 essential amino acids so combining sources ensures adequate intake.

Consuming a sufficient daily supply of high quality proteins ensures the body can perform vital functions related to tissue maintenance, immunity, enzymes and transporting nutrients.

• Functions of Proteins in the Body

Proteins perform a wide array of essential functions to support good health. The primary roles include:

• Structure and Support – Proteins provide structure and support to cells, tissues, organs, muscles, skin, bones, blood vessels and glands. Key structural proteins are collagen, keratin, elastin, fibrinogen, tubulin and actin. Muscles and tendons rely heavily on structural proteins.
• Transport and Storage – Proteins transport and store other molecules within the body including oxygen, lipids, nutrients and water. Hemoglobin transports oxygen in the blood while ferritin stores and releases iron when needed.
• Chemical Reactions and Signals – Enzymes constructed of proteins drive thousands of essential chemical reactions that govern bodily processes. Hormones like insulin regulate development, metabolism, appetite and reproductive function through signaling cascades relying on specialized proteins.
• Immune Function – Antibodies made of proteins defend the body against viruses, bacteria, parasites, fungi and other invaders by binding to them, marking for destruction. Other immune cells have surface proteins that determine response.
• Muscle Contraction – Actin and myosin proteins in muscles interact to create the contractions and movements that enable everything from breathing to lifting weights.
• Tissue Growth and Repair – Growth factors regulate cell reproduction and differentiation for healing wounds and stimulating tissue growth after damage or exercise through intricate protein interactions.

Consuming high-quality dietary proteins provides amino acids so cells can continually construct thousands of unique, specialized proteins crucial for life.

• Importance of Essential Amino Acids

Amino acids are the building blocks of proteins. Among the 20 that exist, the 9 essential amino acids play crucial roles that the body cannot perform itself, making them indispensible in the diet.

• Leucine – Stimulates muscle protein synthesis and growth. Helps regulate blood sugar and growth hormone levels.
• Lysine – Needed for absorbption of calcium, producting hormones, enzymes and antibodies. Helps form collagen to assist tissue repair.
• Methionine – Primary supplier of sulfur which reduces oxidative stress and protects cells. Aids detoxification processes.
• Phenylalanine – Precursor to tyrosine for thyroid hormone, dopamine and noradrenaline to lift mood and boost motivation.
• Threonine – Component of structural proteins like collagen and elastin vital for healthy skin and tissues. Supports fat metabolism in liver.
• Tryptophan – Allows biosynthesis of niacin, serotonin and melatonin. Regulates appetite, sleep cycles and learning ability.
• Valine – Stimulates muscle growth and repair. Provides energy for muscle tissue. Important for mental vigor and coordination.
• Histidine – Needed for growth and tissue repair. Helps protect nerves from damage. Component of hemoglobin for oxygen transport.
• Isoleucine – Boosts energy and endurance. Helps formation of hemoglobin, regulates blood sugar and provides immune system components.

Getting all essential amino acids from high protein foods like meat, dairy, eggs, fish and specific plant combinations is vital for good health and body function.

• Sources of Protein

Protein is available from a variety of whole food sources including both animal and plant-based options:

• Meat – Beef, lamb, pork, and poultry like chicken and turkey provide complete proteins with all essential amino acids. Also rich in iron, zinc and B-vitamins.
• Dairy – Milk, Greek yogurt, cheese like cottage cheese and cheddar deliver calcium in addition to high quality protein.
• Eggs and Egg Whites – Considered the standard for protein quality. Provide all essential amino acids to support muscle growth. Also contain healthy fats and nutrients.
• Fish and Seafood – Salmon, tuna, trout, shrimp and others supply omega-3 fatty acids for heart health alongside protein. Care should be taken regarding possible mercury content.
• Legumes – Beans, lentils, chickpeas, peas have plant-based protein without animal fat or cholesterol. Also packed with fiber. When paired with grains, they form a complete protein profile.
• Nuts and Seeds – Almonds, walnuts, hemp seeds, chia and quinoa seeds offer plant-based protein, fiber and healthy unsaturated fats in one convenient snack.
• Soy Foods – Tofu, tempeh, edamame made from soy provide a vegan protein alternative comparable to animal sources. Also contain probiotics beneficial for digestion. Caution is warranted for hormone-sensitive cancers.

In order to maintain tissue health and proper metabolic functioning, consuming adequate high-quality protein sources is an essential part of a balanced, nutrient-rich diet.

Recommended Intake of Protein

Protein recommendations depend on individual factors including age, sex, body composition goals, activity level and health status.

General Guidelines

The Recommended Daily Allowance (RDA) for protein is 0.8 grams per kilogram of body weight per day for adults. This equals:

• Women: 46 grams/day
• Men: 56 grams/day

However, research indicates the optimal intake for health, performance and maintaining muscle mass is higher than the RDA at:

• 1.2-2.0 grams per kilogram of body weight, or
• 15-25% of total daily calories

Athletes & Active Individuals

Those exercising regularly or training intensely have higher protein needs:

• Endurance athletes: 1.2-1.4 grams per kilogram of weight
• Strength athletes: Up to 2.0 g/kg, or 25-30% of calories

Increased protein aids recovery, builds and repairs muscles broken down during intense physical activity.

Seniors

Aging adults should aim for the higher end of recommendations to preserve muscle, strength and function:

• Men 65+: 1.0-1.3 grams per kilogram
• Women 65+: 1.2 grams per kilogram

Consuming quality protein sources 2-3 times throughout the day optimizes use for tissue growth and repair over the lifespan.

Fats: Essential for Health

Fats: Essential for Health

Though fats long had a negative reputation for causing weight gain, certain types are vital for optimal health. The essential roles dietary fats play include:

Energy Production

Like carbs and protein, fats get broken down into acetyl molecules during digestion to directly fuel cell activities. However, fats provide the most concentrated source of energy – over double the amount per gram as carbs or protein. The body utilizes this efficient energy source during lower intensity exercise, resting state and fuel deficit periods.

Hormone & Cell Regulation

Essential fatty acids cannot be produced by the body. These support cell growth, immune function, metabolism, inflammation through producing hormone-like compounds called eicosanoids. Deficiencies impede vital activities. Omega-3s hold particular import regarding cognitive health and development.

Nutrient Absorption

Fats facilitate the absorption of lipid-soluble antioxidants, magnifying the effects of powerful vitamins A, D, E and K. Dietary fat carries these across digestive cell walls into circulation. Low levels impede their function despite adequate intakes.

While excessive intake of saturated or trans fats harm health, maintaining adequate amounts of beneficial polyunsaturated and monounsaturated fats derived from fish, nuts, seeds, avocado, olive oil and other plant sources is indispensible for energy, vitamin efficacy, cell regulation, immunity and nervous system function.

Overview of Fats

Fats are one of the three macronutrients the body requires in the diet. Getting adequate healthy fat intake is essential for health while limiting disease-promoting varieties.

Functions of Fats

• Concentrated energy source – fats provide over double the calories (9 kcal/g) as carbs or protein
• Aid absorption of fat-soluble vitamins A, D, E, K
• Support cell membrane integrity and hormone production
• Provide insulation and padding for organs
• Assist brain development and nerve transmission

Types of Dietary Fat

• Saturated – Found in animal fats and tropical oils, linked to heart disease risk factors
• Trans fats – Formed through hydrogenation in processed foods, promote inflammation
• Monounsaturated – Found in olive oil, avocados, nuts. May lower heart disease risk
• Polyunsaturated – Essential omega-3 and omega-6 fats. Reduce inflammation.

Fat Recommendations

• Limit saturated fat intake to <10% of total daily calories
• Eliminate trans fats
• Focus on monounsaturated and polyunsaturated sources
• Omega-3s hold particular importance for health
• Balanced ratio of omega-3 to omega-6ylation

Consuming nutrients in their whole food form maximizes health benefits. Variety matters – no single item meets all daily necessities. Combining healthy carbohydrates, proteins and fats derived from plants and animals promotes optimal wellbeing.

• Types of Fats (Saturated, Unsaturated, Trans)

Dietary fats consist of varying configurations of carbon, oxygen and hydrogen molecules referred to as fatty acids. The degree of saturation determines their physical properties and health impacts. The main categories include:

• Saturated Fats – Each carbon atom is bonded to as many hydrogen atoms as possible. Solid at room temperature. Found mainly in animal fats like meat, butter and lard but also coconut and palm oils. Can raise LDL cholesterol when eaten in excess.
• Unsaturated Fats – Have at least one double carbon bond where hydrogen atoms are missing. Remain liquid at room temperature. Considered heart healthier fats. Categories are:
  • Monounsaturated fats – Contain just one double bond. Abundant in plant oils like olive oil and nuts.
  • Polyunsaturated fats – Have two or more double bonds allowing bendability for cell membrane walls and receptors. Omega-3 and omega-6 essential fats fall into this subgroup crucial for nerve signaling and inflammation regulation.
• Trans Fats – Formed through hydrogenation processing to turn healthy oils solid and extend shelf lives. Manmade with hydrogen added across double carbon bonds. Strong evidence links trans fat in processed foods to cardiovascular disease and diabetes.

When selecting fats, focus on replacing disease-promoting saturated and artificial trans fats found in fried and processed items with more monounsaturated and polyunsaturated varieties from fatty fish, nuts, seeds, avocados, olive oil and other plant sources.

• Functions of Fats in the Body

Fats provide a number of structural and functional roles that are essential to maintaining energy balance, healthy cells, hormone regulation and overall wellbeing:

• Energy Storage – The body’s most concentrated source of energy. When carbs are not available, fat from adipose tissue gets metabolized to acetyl-CoA that feeds into cells mitochondria for ATP energy production. Help maintain steady weight.
• Cell Membrane Integrity – Phospholipid bilayers requiring polyunsaturated fats surround and protect cells, forming barriers for important communication between intracellular and extracellular environments.
• Hormone & Gene Regulation – Specific fatty acids interact with nuclear receptors influencing gene expression and control over bodily processes like metabolism, inflammation, reproduction and blood clotting.
• Body Heat Insulation – Subcutaneous fat layers help retain heat to maintain core body temperature in cold weather conditions as well as protecting vital organs.
• Nutrient Absorption – Bile emulsifies fats, allowing the body to access and absorb fat-soluble vitamins A, D, E and K from food necessary to maintain vision, bone health and antioxidant capacity.
• Brain Function & Development – 60% of the brain’s structural matter is composed of lipids. DHA omega-3s hold particular import regarding cognitive health, performance and mood regulation throughout all life stages.

Consuming a balance of quality fats facilitates cell processes related to energy storage, hormones, membrane receptors, temperature, nutrient absorption and healthy brain activities.

• Sources of Healthy Fats

While limiting disease-promoting saturated and trans fats, be sure to include plenty of beneficial monounsaturated and polyunsaturated fats from these sources:

• Nuts and Seeds: Almonds, walnuts, sunflower and flax seeds provide monounsaturated and omega-3 alpha-linolenic fats. They lower LDL and support heart health. Nut butters also supply protein.
• Avocados: Abundant monounsaturated fats allow key fat-soluble nutrient absorption. Provide lutein for eye health. Contain fiber, folate and potassium too.
• Olive Oil: A key component of the Mediterranean diet, extra virgin olive oil provides 75% monounsaturated fatty acids including oleic acid with potent anti-inflammatory effects. Drizzle over salads or veggies.
• Fatty Fish: Cold water fish like salmon, mackerel, tuna, sardines and trout supply anti-inflammatory omega-3s EPA and DHA. Benefits brain, eye and heart health. Canned salmon and sardines also qualify.
• Chia and Flax Seeds: These seeds provide plant-based omega-3 alpha-linolenic acid that gets converted into EPA and DHA. Grind and sprinkle into oatmeal, smoothies or yogurt.
• Tofu and Edamame: Made from soybeans, these complete plant proteins also contain polyunsaturated fats and fiber without cholesterol. Useful for vegan diets.

Emphasize healthy unsaturated fats from whole food sources for the bulk of fat calories, limiting processed trans and saturated varieties which negatively impact health.

Recommended Intake of Fats

While prior guidance advised lower numbers, research now indicates dietary fats are essential for optimal health when consumed in the right proportions from quality sources. Recommendations include:

Total Fat

Making up 20-35% of total daily calories is appropriate for most healthy adults. This equals:

• Women: 44-77 g/day
• Men: 60-93 g/day

Higher athletic training demands may warrant 50% or more from fat. Those seeking weight loss sometimes consume less.

Saturated Fat

Saturated fat should comprise <10% of total calories. Overconsumption raises risks for cardiovascular disease, diabetes and other conditions. That’s 22 g or less for a 2,000 calorie diet.

Trans Fats

Manmade partially hydrogenated trans fats should be eliminated completely given strong links to heart disease, stroke risk, inflammation and insulin resistance. Always read nutrition labels.

Monounsaturated & Polyunsaturated Fats

Most dietary fat should come from heart-healthier monounsaturated (olive oil, nuts) and polyunsaturated omega-3 and omega-6 (fish, seeds) sources. These provide essential fatty acids and protect cell membranes.

Omega-3s

Include fatty fish or supplements providing a minimum of 250–500 mg combined EPA/DHA omega-3s daily for cognitive health and heart benefits. If vegan, opt for DHA-fortified options or algae.

Concentrating fat intake on predominantly unsaturated varieties aids disease prevention efforts while fueling body and brain.