Introduction
Hormones fluctuate across life stages, lifestyle demands shift, and nutritional needs evolve, making the management of energy a complex but essential aspect of wellbeing.
While we often think of energy simply in terms of carbs, fat, calories, and the foods we consume, energy metabolism is far more intricate.
The human body relies on multiple energy systems working in sync to sustain physical activity, cognitive function, and cellular health. These systems include the immediate energy supply from adenosine triphosphate (ATP), the phosphagen system that uses creatine phosphate for short bursts of power, glycolysis that breaks down glucose for energy[1], and oxidative phosphorylation, which uses oxygen to generate sustained energy from fats and carbohydrates[2].
Central to all these systems is the thyroid gland, whose hormones regulate metabolic rate and energy production at the cellular level. Healthy thyroid function ensures efficient energy use and stamina, while imbalances can lead to fatigue and feeling sluggish. Together, these energy systems and hormonal controls enable the body to meet the demands of varying physical activities and life stages.
Optimal female energy is not the product of a single nutrient or food group but rather the harmonious integration of all nutrients consumed consistently over time. While balanced macronutrients provide the fuel, micronutrients act as indispensable cofactors in energy production, hormone synthesis, including thyroid hormones and mental wellbeing. Because some nutrients are often deficient in female diets (due to dietary patterns, physiological losses, or increased life-stage demands) women must prioritise nutrient-rich whole foods and, where necessary, targeted supplementation to support navigating the unique energy challenges of each life stage and thrive physically and mentally.
Many have heard of creatine as a supplement for strength training, but its benefits go far beyond the gym. Creatine is a naturally occurring compound that helps produce quick energy in our cells, especially in the muscles and brain[3]. Women tend to have lower baseline levels than men, and hormonal changes reduce them even further[4]. Research shows that creatine supplementation can help boost cellular energy, reduce fatigue, support brain function, and maintain muscle mass, making it a powerful ally for women’s health across all ages[5].
Hormones play a critical role in regulating these energy pathways.
For women, key hormones such as oestrogen, progesterone, thyroid hormones, insulin, and cortisol influence metabolism, appetite, muscle function, and brain energy[6]. For example, oestrogen enhances mitochondrial efficiency and energy production, while cortisol helps manage stress and energy mobilisation[7]. Fluctuations in these hormones during menstrual cycles, pregnancy, perimenopause, and menopause can cause noticeable shifts in energy availability and fatigue levels[8].
Nutrition supports these complex biochemical and hormonal processes far beyond simple calorie intake.
Nutrients like iron and folate support oxygen transport and red blood cell formation, essential for delivering energy to tissues[9]. Omega-3 fatty acids aid brain function and reduce inflammation[10], while magnesium[11] and B vitamins act as co-factors in enzymatic reactions vital to energy production[12]. Even external factors like sunlight influence vitamin D synthesis, which impacts muscle function and mood and therefore energy[13].
Moreover, gut health is often overlooked yet is central to energy regulation. A balanced gut microbiome supports nutrient absorption, immune function, and even neurotransmitter production, all of which affect overall energy[14].
Why Energy Levels Fluctuate in Women
Women are biologically distinct in how they produce, utilise, and manage energy, largely due to the profound influence of hormonal fluctuations that occur throughout the menstrual cycle, pregnancy, perimenopause, and menopause[15].
“These hormonal changes directly affect metabolic rate, nutrient requirements, and mental energy levels, shaping how women experience fatigue, stamina, and cognitive focus at different times in their lives. Beyond biology, physical demands ranging from parental and professional responsibilities to the natural processes of ageing all add layers of complexity to women’s energy management, making personalised strategies essential”.
Hormones
Women, due to their unique hormonal milieu[nr3] [16], may experience variations in how effectively these energy systems function[17]. For example, fluctuating levels of oestrogen and progesterone across the menstrual cycle can influence substrate utilisation, often shifting energy metabolism towards greater fat oxidation during the luteal phase[18]. During pregnancy, increased metabolic demands and hormonal shifts further alter energy system efficiency[19]. In perimenopause and menopause, declining oestrogen levels can impact mitochondrial function and muscle metabolism, potentially reducing endurance and strength[20].
These physiological nuances also affect motivation and mental energy.
Hormonal changes influence neurotransmitters like serotonin and dopamine, which regulate mood, focus, and motivation, factors critical for sustaining physical activity and overall vitality[21].
Understanding these distinctive energy dynamics is key to tailoring nutrition, exercise, and lifestyle interventions that optimise energy production and utilisation in women throughout their life stages[22]. Such personalised approaches can help enhance physical performance, mental clarity, and resilience against fatigue[23], [24].
Hormonal Influence on Energy System Efficiency
During the follicular phase (the first half of the menstrual cycle), rising oestrogen promotes greater reliance on fat as a fuel source, preserving glycogen and potentially improving endurance capacity[25]. Therefore, this phase often supports better performance in aerobic activities.
- In the luteal phase, increased progesterone raises body temperature and metabolic rate, shifting substrate use more towards carbohydrates, which can affect energy availability during exercise and increase fatigue.
- In perimenopause and menopause, declining oestrogen can impair mitochondrial efficiency and muscle metabolism, reducing the oxidative system’s capacity. This may lead to decreased endurance and slower recovery. Strength training and creatine supplementation become particularly important to preserve muscle mass and energy metabolism.
Understanding how these energy systems interplay with hormonal changes and lifestyle can help women optimise their activity choices, nutrition, and rest to maximise energy throughout the day and across life stages.
A Nutritional Perspective on Energy and Women’s Health
From a nutritional standpoint, maintaining optimal energy levels in women demands an integrated, life-stage-specific approach. Women’s unique physiology, marked by cyclical hormonal shifts throughout the menstrual cycle, perimenopause, and menopause, profoundly influences metabolism, appetite, sleep patterns, stress responses, and ultimately, energy balance.
Unlike men, women’s energy needs are dynamic and fluctuate in tandem with hormonal changes, making it essential to consider the complexity between hormones, micronutrients, digestion, and mental wellbeing when designing nutritional strategies.
All Nutrients Are Essential, But Some Become Particularly Integral
It’s important to recognise that all nutrients are necessary all the time to support the body’s countless biochemical processes. Energy metabolism, hormone synthesis, immune function, cognitive clarity, and cellular repair all require a steady supply of diverse nutrients. However, certain nutrients are especially integral to female health because of their roles in hormone regulation, across lifestages, and furthermore, these nutrients are also commonly deficient in women’s diets[26]. Addressing these key nutrients can have a profound impact on maintaining sustained physical and mental energy.
Macronutrient Balance and Female Physiology
A balanced intake of macronutrients (carbohydrates, proteins, and fats) is foundational for sustained energy production and overall wellbeing. However, women may need a more nuanced macronutrient approach that adapts to their hormonal profile and life stage, including close attention to thyroid health and gut function, which are both essential for optimal energy.
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Carbohydrates:
Women benefit most from whole, complex carbohydrate sources such as oats, quinoa, sweet potatoes, and legumes. These provide a steady, gradual release of glucose into the bloodstream, helping to avoid sudden energy crashes or mood fluctuations. Notably, for many women insulin sensitivity can decline during the luteal phase of the menstrual cycle[27], making blood sugar regulation especially important to maintain stable energy levels and prevent fatigue or irritability.
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Protein:
Protein supports not only muscle maintenance but also neurotransmitter production, which is critical for regulating mood and cognitive energy[28]. Including high-quality protein sources such as eggs, poultry, tofu, lentils, and fish across the day help to stabilise energy, enhance satiety, and support hormonal balance.
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Healthy Fats:
Fats from sources like avocados, nuts, seeds, and oily fish are vital for hormone synthesis and brain health; two cornerstones of mental energy[29]. Essential fatty acids like omega-3s support cell membrane integrity[30] and reduce inflammation[31], which may improve mood and cognitive function, particularly during hormonally sensitive phases.
Micronutrient Spotlight
Several micronutrients are especially crucial to female energy metabolism and wellbeing but are frequently deficient, making targeted nutritional attention necessary:
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Iron:
Iron deficiency anaemia is one of the leading causes of fatigue in menstruating women due to regular blood loss. Iron is essential for oxygen transport in red blood cells, directly impacting cellular energy production[32]. Good dietary sources include red meat, lentils, pumpkin seeds, and fortified cereals. Consuming these with vitamin C-rich foods like citrus fruits or bell peppers enhances iron absorption.
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Iodine:
Iodine is an essential trace mineral required for the synthesis of thyroid hormones, which regulate metabolism, energy production, and neurological function[33]. Deficiency can impair thyroid hormone production leading to hypothyroidism, characterised by fatigue, weight gain, and cognitive slowing. Dietary sources include iodised salt, seaweed, dairy products, and seafood.
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Magnesium:
Magnesium is a key mineral in many of the body’s functions. With regard to energy magnesium is key in ATP (energy molecule) production and nerve function[34]. It also plays a role in alleviating premenstrual symptoms and improving sleep quality, two significant contributors to maintaining female energy balance.
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Vitamin D:
Vitamin D plays many roles, but is critical in supporting energy by enhancing mitochondrial function (often called the cells battery) while also boosting immune resilience and stabilising mood[35]. These combined effects help sustain consistent energy levels and a greater sense of vitality throughout the day
The B vitamin group is integral to energy metabolism and particularly important for women throughout lifestages along with stress management, and hormone balance. These vitamins have many roles, but essentially act as essential cofactors for enzymatic reactions involved in the breakdown of carbohydrates, fats, and proteins into usable energy (ATP), supporting both physical and mental performance[36].
Key B vitamins include:
- B1 (Thiamine): Helps combat energy dips, especially pre-menstrual, by supporting carbohydrate metabolism[37].
- B2 (Riboflavin): Facilitates fat and carbohydrate metabolism[38].
- B3 (Niacin): Supports stress resilience, skin health, and contributes to DNA repair[39].
- B5 (Pantothenic Acid): Essential for adrenal function, synthesis of coenzyme A, and managing hormonal stress[40].
- B6 (Pyridoxine): Has been linked with reducing for PMS symptom management (yet more research is needed), serotonin production, immune support, and neurotransmitter synthesis[41].
- B7 (Biotin): Important for converting food into energy, fatty acid synthesis, and maintaining healthy hair and nails[42].
- B9 (Folate): Folate helps your body make DNA and red blood cells. It’s also needed for cell growth and helping to build and break down protein. Folate is required at every stage of life (folic acid is the chemical form[43]), but it’s particularly important for women just before and in the first three months of pregnancy[44].
- B12 (Cobalamin): Crucial for cognitive clarity, red blood cell production, DNA synthesis, and reducing fatigue[45].
Ensuring adequate intake of B vitamins through nutrient-dense foods such as whole grains, dark leafy greens, eggs, dairy, legumes, and lean meats is essential for supporting energy metabolism and hormonal health throughout a woman’s life.
Thyroid Function and Nutritional Support:
The thyroid gland is a master regulator of metabolism and energy production through its hormones (thyroxine/T4 and triiodothyronine/T3)[46]. These hormones control basal metabolic rate, thermogenesis, and cellular oxygen consumption, all of which profoundly influence how energetic or sluggish one feels. Thyroid dysfunction, especially hypothyroidism, is common in women and can lead to persistent fatigue, cognitive dulling, and weight changes[47].
Optimal thyroid function depends on key nutrients:
- Iodine: Essential for the production of thyroid hormones. Dietary sources include iodised salt, seaweed, dairy, and fish.
- Selenium: Required for the conversion of T4 into the active T3 hormone and protects the thyroid gland from oxidative damage. Brazil nuts, seafood, and eggs are rich sources.
- Zinc: Important for thyroid hormone metabolism and immune function. Found in meat, shellfish, legumes, and seeds.
- Iron: Necessary for thyroid hormone synthesis and also involved in oxygen transport.
- Vitamin D: Supports immune regulation and has emerging links with thyroid health.
Supporting the thyroid through adequate intake of these vitamins and minerals is essential for maintaining energy metabolism and overall vitality.
Poor gut health is often characterised by poor digestion, constipation, or imbalanced microbiota which can leave you feeling tired[48], bloated[49], and mentally foggy[50]. Poor gut health impairs nutrient absorption and disrupts the gut-brain axis, which plays a critical role in mood, cognition, and energy regulation. Therefore, maintaining gut health through sufficient fibre intake and hydration directly contributes to sustained physical and mental energy.
Fibre and Gut Health:
- Fiber-rich foods such as fruits, vegetables, whole grains, nuts, fermented foods and seeds support digestive health by promoting regular bowel movements and feeding beneficial gut bacteria[51]. These bacteria ferment fibre to produce short-chain fatty acids (SCFAs), which are crucial energy sources for colon cells and have systemic anti-inflammatory effects that support metabolic health.
- Gut health influences how nutrients are absorbed and how energy is utilised. The gut-brain axis also plays a role in mood and fatigue. A high-fibre diet with prebiotics (onions, garlic, bananas) and probiotics (yogurt, kefir, fermented vegetables) supports digestion and immunity.
- Blood sugar stability is equally crucial. Rapid spikes and drops in blood sugar can lead to energy crashes, mood swings, and cravings. Focus on low-GI foods like oats, sweet potatoes, beans, and pairing carbohydrates with protein or healthy fats to extend energy release.
