Cannot lose weight

Start with something other than blame

I want to say one thing before the list, because it changes how the rest reads.

If you have been told to eat less and move more, and you have done exactly that, and nothing happened, you were not given bad arithmetic. You were given incomplete arithmetic.

Energy balance is real. It is also not the whole system. Hormones determine what your body does with the energy it has, how hard it defends its current weight, how hungry you are at four in the afternoon, and how much of a deficit it will tolerate before quietly reducing what you burn.

So the question is not whether you are trying hard enough. The question is which of the variables underneath is currently working against the effort.

Most of them are measurable. That is the useful part.

And one of them is not measurable at all, and is probably the biggest single lever on this page. We will get to it.

Why nobody has found it yet

Here is the fact that should get your attention.

A standard annual panel measures fasting glucose. It does not measure fasting insulin.

That sounds like a technicality. It is the whole thing.

Insulin is the hormone that tells your body to store fat and stops it releasing stored fat. When your cells respond less well to insulin, your pancreas compensates by making more of it. More insulin does the job. Glucose stays normal.

Which means your fasting glucose can read 90 for a decade while your insulin has been climbing the entire time, doing more work each year to hold that same number.

And the entire time, every annual physical returns the same sentence: your blood sugar is fine.

It is fine. It is being held fine, by a hormone that also happens to govern fat storage, at a level nobody measured.

That gap is why so many people are told there is nothing wrong while feeling their body defend every kilogram. The test that would have shown it is fasting insulin, it costs one line on a lab order, and almost nobody runs it.

The causes, and what separates each

Read this as a map rather than a diagnosis. Two or three of these usually run together, which is exactly why fixing one thing at a time so often does nothing.

Insulin resistance. The biggest single metabolic variable here, and the most commonly unmeasured. Distinguishing markers: fasting insulin with HbA1c. You can also check your triglyceride to HDL ratio free, using a lipid panel already in your records.

Thyroid running slow. Lowers metabolic rate genuinely, though usually by less than people hope. Distinguishing markers: a full thyroid panel with free T3, free T4 and antibodies. TSH alone is a third of the question, since it measures the pituitary's instruction rather than the hormone arriving.

Short sleep. Measurably reduces insulin sensitivity and shifts appetite hormones toward hunger. Distinguishing sign: you are averaging under seven hours. No blood test involved, and it is the largest lever most people are not pulling.

Medications. Some antidepressants, antipsychotics, corticosteroids, beta blockers, certain diabetes drugs and hormonal contraceptives are associated with weight gain. Distinguishing move: read your list, then raise it with your prescriber. Never stop anything over a website.

Intake higher than it feels. Dietary recall research consistently finds underestimation across all body sizes, including among trained professionals. Distinguishing test: one week of honest weighed logging, treated as a measurement rather than a verdict. It either finds a gap or rules one out.

Metabolic adaptation from prolonged restriction. A smaller body burns less, and long restriction lowers rate somewhat further while raising hunger. Distinguishing sign: you lost weight, then stalled, and eating even less made it worse. The response is muscle and maintenance periods, not more restriction.

Chronic stress load. Affects sleep, blood sugar regulation and eating behaviour at once. Not measurable in any useful way, and worth addressing regardless of whether a test names it.

The lever almost nobody pulls

Alright. Here is the part that reframes this, and it has nothing to do with food.

In 2021 the Journal of Clinical Endocrinology and Metabolism published a randomised, double-blind, in-laboratory crossover study. Thirty-four healthy young men, four nights of sleep restricted to four hours a night, done twice: once with cortisol and testosterone held fixed by a clamp, once with placebo.

Sleep restriction alone produced hyperinsulinaemia, hyperglycaemia and overall insulin resistance. Every one of those at p less than 0.001.

Four nights. Healthy young men. No change in diet.

And when cortisol and testosterone were clamped so they could not move, the development of insulin resistance and hyperinsulinaemia was cut by roughly half.

Sit with what that means for anyone trying to lose weight on six hours of sleep. You are not merely tired. You are running a measurably more insulin resistant metabolism than the same body would have on eight hours, and insulin is the hormone that governs whether stored fat gets released.

That study was four nights. Most people reading this have been doing it for years.

So here is the uncomfortable version. If you are sleeping under seven hours and eating carefully, the food is not the variable you should be adjusting next. The sleep is. And it is free.

Where the honest hedge goes

I am not a doctor and I am not diagnosing anyone, and I am not going to promise you a number on a scale.

I want to be careful with thyroid in particular, because it is the most commonly hoped-for explanation and the evidence asks for restraint. A genuinely underactive thyroid does lower metabolic rate and treating it does help. But treating a thyroid that is actually working normally will not produce weight loss, and a 2020 analysis nested in the randomised TRUST trial found no improvement in fatigability from thyroid hormone therapy in older adults with mild subclinical hypothyroidism after a year. Test properly, treat what is genuinely there, and do not expect the thyroid to be the whole answer.

I also will not tell you that calories do not matter. They do. What I will tell you is that hormones determine how hard the body defends its position, and that measuring insulin is how you find out whether that defence is unusually strong.

Some presentations need a doctor rather than a plan. Rapid unexplained weight gain, facial swelling with purple stretch marks and easy bruising, or leg swelling with breathlessness all point at specific conditions.

And if the effort around this has become distressing, or if food has become something you fight with, that matters in its own right and deserves proper support rather than a better spreadsheet.

I am not saying insulin is your answer. I am saying it is a variable, a large one, and it is one almost nobody checks.

So. Here is what I would actually do.

Tonight, at no cost. Set a bedtime that gives you seven and a half hours, and treat it as the appointment it is. Given the research above, this is the highest return change on the page and it costs nothing.

Tonight, also. Calculate your triglyceride to HDL ratio from a lipid panel already in your records. Free, and one of the better flags for insulin resistance.

This week. Read your medication list and mark anything you are unsure about, then take that list to your prescriber. Do not stop anything yourself.

Start lifting. Resistance training two or three times a week builds the tissue that stores most of your glucose, which is the most direct non-pharmaceutical route to better insulin sensitivity. Walking after meals stacks on top of it.

When you test, order the pairing that answers the most. Fasting insulin with HbA1c, plus a full thyroid panel. One draw. Insulin is the one your annual physical has never run.

Add the supporting markers. Ferritin with hs-CRP, and vitamin D3.

Then run one honest week of logging. Not forever, and not as a punishment. As a measurement that either finds something or lets you stop wondering.

The bigger project. Take the whole set to a good functional medicine doctor who reads it as a system.

None of this has to happen this week. But tonight you can go to bed ninety minutes earlier.

You are not lacking discipline. You are a system with a hormone that decides what to do with the fuel, running on less sleep than it needs, being judged entirely on the arithmetic.

Your body is not broken. It is blocked. And for a great many people the block is a hormone nobody measured and an hour of sleep nobody counted.

Go to bed earlier tonight.