Why Underfueling Is Sabotaging Your Weight, Mood, and Hormones (and What to Do Instead)

Why Underfueling Is Sabotaging Your Weight, Mood, and Hormones (and What to Do Instead)

If you’re in perimenopause or menopause, chances are you’ve been exposed to—or tried—extreme fad diets. Low-calorie plans, carb elimination, prolonged fasting… they’re often marketed as the solution to stubborn weight gain and hormonal changes.

But here’s the truth: chronic dieting and underfueling are neither sustainable nor supportive of women’s health, especially during midlife.

While weight may drop quickly when eating 600 calories a day or cutting out entire food groups, this approach often backfires. Underfueling disrupts your metabolism, mood, and hormones, making it harder to feel energized, balanced, and at peace with food.

The Hidden Cost of Eating Less

As women, we’ve been conditioned by diet culture to “be smaller” and take up less space—including eating as little as possible. But surviving on a few leaves of lettuce for lunch is not a badge of discipline; it’s detrimental to your health.

Chronic underfueling can lead to:

  • Weight plateaus or unexplained weight gain

  • Mood swings, anxiety, and irritability

  • Hormonal imbalance and cycle irregularities

Your body needs adequate fuel to function properly. When it senses scarcity, it shifts into survival mode—holding onto fat while breaking down valuable muscle tissue for energy.

What Is Underfueling?

Underfueling occurs when you consistently fail to meet your body’s energy and nutrient needs. This sends a signal that resources are scarce, triggering metabolic and hormonal disruption.

Common signs of underfueling include:

  • Skipping meals

  • Extreme intermittent fasting

  • Restricting food groups (especially carbohydrates)

  • Not eating enough to match activity levels

Women are particularly vulnerable due to:

  • Busy schedules and caregiving demands

  • Diet culture messaging

  • Fear of weight gain

  • Nutrition misinformation

How Underfueling Sabotages Weight Loss

When your body is underfueled, whether intentionally or unintentionally, it adapts in ways that work against weight loss.

Your body may:

  • Slow its resting metabolic rate to conserve energy

  • Increase fat storage as a protective mechanism

  • Become more resistant to fat loss over time

The Role of Ghrelin and Leptin

Ghrelin (hunger hormone) and leptin (satiety hormone) regulate appetite and fullness. Chronic restriction disrupts this balance.

When underfueled:

  • Ghrelin increases, driving intense hunger

  • Leptin signaling weakens, making it harder to feel satisfied

This can lead to overeating, guilt, and a frustrating cycle that feels out of control—but isn’t a lack of willpower.

A Sustainable Approach to Weight Loss

Instead of eating less, focus on eating consistently and adequately:

  • Eat at regular intervals

  • Eat within 1–2 hours of waking

  • Include protein, fat, and fiber at every meal and snack

The Food–Mood Connection

Your brain runs primarily on glucose. While it can adapt to ketones, glucose is its preferred fuel—especially for concentration, emotional regulation, and memory.

When your brain doesn’t receive enough energy, you may experience:

  • Anxiety and irritability

  • Low mood or depressive symptoms

  • Brain fog and difficulty focusing

Blood sugar balance also matters. Meals made up of only quick-digesting carbohydrates can cause crashes that worsen mood and energy. Protein, healthy fats, and complex carbohydrates provide steady fuel for both the brain and body.

Hormones Under Stress

Underfueling is a physiological stressor. When layered on top of daily stress—traffic, work deadlines, caregiving—cortisol levels rise, pushing the body into fight-or-flight mode.

Elevated cortisol:

  • Raises blood sugar levels

  • Promotes insulin resistance

  • Encourages fat storage, especially around the midsection

Additional hormonal impacts of underfueling may include:

  • Dysregulated thyroid function

  • Irregular or missing menstrual cycles

  • Worsened PMS symptoms

Signs You May Be Underfueling

  • Extreme fatigue

  • Weight plateaus or gain despite low calorie intake

  • Menstrual changes or missing periods

  • Intense cravings or food obsession

  • Cold intolerance

  • Difficulty sleeping

  • Trouble building muscle

What Your Body Actually Needs

There is no one-size-fits-all diet—but every body requires adequate calories, macronutrients, and micronutrients to thrive.

Macronutrients Matter

Protein

Supports hormone production, muscle synthesis, bone health, glucose metabolism, and cellular communication.


Aim for ~25–30 grams per meal as a baseline.

Sources: eggs, dairy, legumes, beans, nuts, seeds, pasture-raised meats, poultry

Healthy Fats

Essential for hormone production, brain health, and inflammation regulation.

Sources: avocados, olive oil, nuts, seeds, fatty fish (salmon, sardines, tuna)

Carbohydrates

Critical for energy, thyroid health, and progesterone production.

Sources:

  • Root vegetables (sweet potatoes, squash, carrots)

  • Fruit (berries, apples, citrus, bananas)

  • Whole grains (oats, brown rice, millet, barley)

  • Legumes and pulses

Reframing Your Mindset Around Food

You do not need to earn food.


You do not need to restrict to be worthy.

Food is information for your cells, not a moral issue. Some foods provide more supportive information than others, but deprivation is never the goal.

Your body is the vessel that allows you to live your life. Treat it with respect, curiosity, and gratitude.

Learning to trust hunger and fullness cues may take time—especially after years of dieting. Mindful eating practices can help support this process.

Healing metabolic and hormonal health is often the first step toward achieving a healthy, sustainable weight.

Conclusion: Food Is Not the Enemy

Underfueling sabotages your weight goals, hormones, and mood—but your body is resilient. It wants to feel safe, supported, and nourished.

If you’re struggling with weight changes, low energy, or hormonal imbalance and want personalized support, I’d love to help. I offer 1:1 coaching as a certified nutritionist and women’s health coach to help you restore balance and feel vibrant again.

You deserve to thrive!

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