Guest post by Keriann, Clinical Nutritionist (BHSc), founder of How It Heals

You are eating less than anyone you know. You skip breakfast, you order the salad, you finish the day proud of how little you managed on. And the scale has not moved in months. If anything, you feel puffier, colder, more tired and more anxious than when you started.

You have probably been told the answer is more discipline. Eat less. Move more. Try harder.

I want to tell you something different, because I lived this. The problem is not your willpower. The problem is that chronic undereating is actively working against your metabolism, and the longer you stay in that hole, the harder your body fights to keep the weight on.

Your body does not know you are dieting. It thinks you are starving.

Your metabolism is not a fixed number. It is a living system that constantly adjusts to the energy coming in. When you consistently eat well below what your body needs, it does not just burn fat and carry on. It adapts.

This is called adaptive thermogenesis, and it looks like this:

Your thyroid downregulates. Your body converts less T4 into active T3, the hormone that sets your metabolic rate, and shunts more of it into reverse T3, which essentially puts the brakes on. Your labs might still say "normal" while your metabolism quietly runs cold. This is why so many women eating 1200 calories a day feel freezing, exhausted and stuck.

You lose muscle, not just fat. When energy is scarce, your body breaks down muscle tissue to make glucose. Muscle is your most metabolically expensive tissue. Every kilo you lose lowers the number of calories you burn at rest, which means the diet that "worked" last year now needs to be even more extreme to get the same result.

Cortisol climbs. Undereating is a stressor. Your body responds with elevated cortisol, which drives fluid retention, blood sugar swings, poor sleep and stubborn fat storage around your middle. That puffy, wired but tired feeling is not in your head. It is your stress physiology doing exactly what it was designed to do.

Hunger hormones rebel. Leptin falls, ghrelin rises, and your brain becomes obsessed with food. The 9pm pantry raid after a "perfect" day of eating is not a character flaw. It is a survival mechanism.fresh produce

So you end up in the worst possible position: eating very little, burning very little, storing stress weight, and blaming yourself for all of it.

Why nobody told you this

Conventional weight loss advice treats your body like a calculator. Calories in, calories out, end of story. And in a lab, over a short window, that maths holds up.

But you do not live in a lab. You live in a body with a thyroid, an adrenal system, a menstrual cycle and decades of dieting history. The "eat less" model completely ignores what chronic restriction does to the hormones that govern where energy goes. It is not that the advice is entirely wrong. It is that it is dangerously incomplete, and women are the ones paying for it.

Your body is not broken. It is responding intelligently to an environment of scarcity and stress. Change the environment, and the response changes too.

How to actually restore your metabolism

The way out is counterintuitive: you have to feed your metabolism before you can ask it to burn. And the most powerful place to start is your fruit and veg.

Eat more, not less, starting with fresh produce. Most of the women I work with need to dramatically increase the volume of real food on their plate, and fresh vegetables and fruit are the safest, most effective way to do it. Produce is dense in the exact nutrients a downregulated metabolism is starving for while keeping blood sugar steady and your nervous system calm. Aim to more than fill half your plate with vegetables at every meal, then add fruit between meals rather than restricting it. Abundance is the signal that tells your body the famine is over, and that is what allows thyroid output to recover and cortisol to settle.

Nutrient density matters more than calories. Your thyroid needs selenium, zinc and iodine. Your mitochondria need magnesium and B vitamins. Your liver needs the compounds in leafy greens and brassicas to clear excess hormones properly. A body can be overfed on packaged food and completely undernourished at the cellular level, and that undernourishment reads as stress. Fresh, seasonal produce grown in healthy soil is the most concentrated source of these nutrients you can eat. Soil health directly determines the mineral content of the food grown in it, which is why produce from regenerative and spray free farms is not just a nicer version of the same thing.

Go spray free where you can. This part rarely gets mentioned in weight loss conversations, but it matters. Many common pesticides are endocrine disruptors, meaning they interfere with the same hormonal systems (thyroid, estrogen, insulin) that govern your metabolism. When you are trying to restore a stressed metabolic system, eating heaps of produce and lowering the chemical load coming in with it is working both sides of the equation at once.

Anchor every meal with protein. A palm sized serve or more of quality protein at breakfast, lunch and dinner protects your muscle, keeps blood sugar stable, and has the highest thermic effect of any macronutrient, meaning your body burns more energy simply digesting it. Pair it with that half plate of vegetables and you have the template.

Lift something heavy. Building muscle is the single most powerful long term investment in your metabolic rate. You cannot out restrict a shrinking engine, but you can build a bigger one.

Fill your fridge, not your rules

This is genuinely where I tell every client to begin, because you cannot eat abundantly from a kitchen stocked for a 1990s diet.

Ditch the low fat, low calorie packets promising weight loss and replace them with real food: a fridge full of seasonal vegetables, fruit, leafy greens, quality protein, eggs and good fats. When fresh produce is the most available thing in your kitchen, eating heaps of it stops being a project and becomes the default. A weekly box of spray free, seasonal fruit and veg landing on your doorstep is one of the simplest ways I know to make the healthy choice the easy one.

If you have been stuck for years, there is usually more to the story

Sometimes eating more and eating real food is enough to turn things around. But if you have been undereating for a decade, cycling through diets since your twenties, or your symptoms run deeper than weight (exhaustion, hair loss, cycle changes, gut issues, anxiety), then guessing is not a strategy.

This is exactly what the Female Biological Reset was built for. We use functional testing to look at what is actually happening in your thyroid, your metabolic markers, your minerals and your genes, then rebuild your metabolism with a personalised, food first protocol. No more white knuckling 1200 calories and hoping.

If that sounds like the conversation you have been waiting to have, book a free clarity call and let’s look at what your body has been trying to tell you.

Your metabolism is not the enemy. It has been protecting you this whole time. It is time to work with it.

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Keriann is a Clinical Nutritionist (BHSc) and the founder of How It Heals, a functional health practice helping women uncover the real drivers behind hormonal and metabolic symptoms through functional testing and personalised, food first nutrition. She works with clients across Australia and internationally via telehealth.