PMOS and Weight - Is there a Best Diet for PCOS and Weight Loss?
If you have PMOS (formerly PCOS) and have spent some time in a doctor’s office or searching for PMOS (previously PCOS) advice online, you may be very familiar with the recommendation to “just lose some weight”.
Yet, as someone with PMOS, this advice may feel super challenging, and the medical expectations may feel somewhat unachievable. Perhaps you feel like you’re doing so many things right, to see the scale stay exactly where it is, and you are left wondering ‘why is it so hard to lose weight with PCOS?’
You may be caught up in a cycle of blame and confusion, and the feeling that you just aren’t trying hard enough. But I want to reassure you right now that this is not a willpower problem.
Because PMOS is a whole-body condition that can affect hormones, insulin levels and the way your body converts food into energy, meaning that managing your weight is more complex than the classic “calories in vs calories out” approach.
In this blog post, we’re moving away from the pressure of extreme restriction and looking at how you can actually support your body’s unique needs. We will explore why the traditional “eat less, move more” advice often fails and what the best diet for PMOS/PCOS and weight loss looks like when we prioritise health over the number on the scale.
Why is it so hard to lose weight with PCOS
If you’ve struggled, it’s not because you aren’t trying hard enough. Research confirms that weight management with PCOS is hard, and the underlying biological pathways driving PMOS make it even more challenging for standard weight loss advice to be effective (1).
Here is what is actually happening:
Insulin resistance: Higher levels of insulin prevent your body from efficiently breaking down fat for fuel, regardless of your calorie intake.
A slower metabolic pace: People with PCOS may have a lower “Basal Metabolic Rate” (2). This means your body may burn fewer calories at rest.
Appetite regulation: Disrupted appetite hormones can send faulty ‘hunger’ signals to the brain. Those intense cravings aren’t a lack of willpower - they are biological signals that your body needs energy.
Persistent exhaustion: When your body struggles to use energy efficiently, you feel exhausted. This makes “moving more” feel like an unmanageable physical task.
These metabolic hurdles are completely real and many of my clients talk about this constant uphill struggle. If this feels difficult for you too, know that it is not your fault, and not a failure of your character or lack of willpower.
Should you lose weight with PCOS?
The answer to this is nuanced and depends entirely on your individual goals. While weight loss may be the first thing mentioned in a doctor’s office, it is not the only way to manage PCOS effectively.
Here is what the evidence actually shows:
The clinical side: The latest guidelines indicate that for those with a higher Body Mass Index (BMI) (although I don’t like to use BMI on a day to day basis, this is what much of the research and guidelines use/refer to), a modest weight reduction of 5 - 10%, potentially improves insulin sensitivity and helps to regulate ovulation (1).
Health gains without weight loss: Crucially, you can actually achieve significant health wins - like improved energy, better mood, and more regular cycles - without the scale moving at all. Many of these improvements happen through consistent lifestyle shifts, regardless of changes in body size.
Defining your priorities: For some, weight loss is a specific goal. For others, the focus might be on improving your skin, regulating your cycle, managing “brain fog”, or healing your relationship with food after years of restriction. All of these priorities are valid and individual - you need to decide what is most important for you!
The Bottom Line: Your health is about how your body functions and how you feel every day. Whether weight loss is a goal for you or not, the focus should be on sustainable habits that support your hormones rather than a specific number on the scale.
If you have questions about PCOS or your diet to support you in your PCOS journey, book a free enquiry call with Claire Pettitt, a PCOS specialist dietitian, to find out how 1:1 support can help you.
Why eat less, move more advice is not helpful
Traditional advice treats PMOS/PCOS like a simple math equation, but research into lived experiences shows that this oversimplified message often does more harm than good (3).
Beyond the biological hurdles, this approach fails because:
Other causes may get missed: Over-focusing on the scale can cause other symptoms - like pain or mental health - to be overlooked, making you feel judged rather than supported.
Lack of practical guidance: Being told to “eat less” offers a goal without practical guidance. It leaves many feeling dismissed, expecting to get results without tools tailored to their needs.
The Emotional Toll is Too High: Calling weight a willpower problem is incorrect. If you’ve tried everything without success, it is easy to feel disheartened, even when it’s not your fault.
Your Inner Trust Gets Broken: Rigid dieting forces you to ignore your body’s signals, often leading to a stressful all-or-nothing relationship with food that is impossible to maintain.
Why fad diets and quick fixes don’t work
Fad diets prioritise short-term rules over long-term support, often causing more harm than good.
If you have been on a restrictive diet of some kind then I am sure you can relate to that constant pressure to ‘eat the right thing’, or the negative thoughts you have when you fancy a restricted food. Well, severe restriction acts as a biological stressor, spiking cortisol, the body’s stress hormone (4). For those with PCOS, this extra stress can worsen inflammation and metabolic health.
Research shows most dieters regain their weight within a few years, often gaining back more than they initially lost (5). This weight cycling is more taxing on your body than maintaining a stable weight.
Rigid rules also disrupt your relationship with food, turning eating into a source of anxiety. When these unsustainable rules inevitably clash with real life, the resulting guilt harms your mental health and self-esteem.
What to avoid when trying to lose weight
When you are looking for progress, it is just as important to know what to leave behind. Certain habits can become obstacles to both your metabolic health and your mental well-being:
Crash diets and cutting out food groups: Severe restriction and eliminating entire food groups (like all carbs) are rarely sustainable and may lead to nutritional deficiencies. These extreme diets often trigger weight cycling - losing and regaining weight - which is linked to worse physical and psychological health outcomes (6).
Obsessive tracking: If logging every calorie or weighing every gram of food causes you anxiety, it is likely doing more harm than good. A “weight-inclusive” approach suggests that focusing on healthy behaviours (like balanced eating) rather than just the number on the scale leads to better health markers like blood pressure and mood (6).
The social media trap: Comparing your real-life journey to curated images online is a major source of distress. Research shows that appearance comparisons made through social media are more damaging to your mood and body satisfaction than comparisons made in person (7).
Expecting fast results: Sustainable changes to your health takes time. Expecting the scale to drop overnight leads to a cycle of frustration. Focus on “non-scale victories” - like having more energy to get through your day, eating your oily fish twice a week, or feeling less “brain fog”.
Best diet approach for weight loss and PCOS
A more sustainable approach is to try to focus on stabilising insulin, balancing blood sugars and lowering inflammation by including foods rather than focus on restricting.
Blood sugar stability: Pair high-fibre carbs with protein and fats to prevent the insulin spikes that drive weight gain.
The plate method: Fill half your plate with veggies and a quarter each with protein and complex carbs. This ensures adequate fibre intake necessary to support gut health and satiety (8).
Regular eating: Consistent meals prevent energy crashes and “sugar-seeking” hunger.
The Mediterranean way: This anti-inflammatory pattern (nuts, fish, olive oil) is proven to improve ovulation and metabolic health more effectively than traditional low-fat dieting (9).
Lifestyle shifts: Prioritise 7-9 hours of sleep and post-meal walks to naturally lower insulin resistance and manage cortisol.
Medications to lose weight with PCOS
Medication is one clinical tool used to manage insulin resistance, but it is not a quick solution. International guidelines (1) indicate it may be considered if lifestyle changes alone haven’t improved metabolic markers, if your BMI is 30 or over, or BMI is 27 or more with PMOS/PCOS complications. For some people with PMOS, weight loss medications can be a valuable tool, but it isn’t recommended for everyone and there are many different forms of weight loss medications out there.
Ozempic, Mounjaro and PCOS
GLP-1s (Ozempic) and dual-action medications like Mounjaro target increased appetite caused by insulin resistance, making you feel less hungry. However, it is vital to seek help from a healthcare professional if you are considering any of the above! It is important that you don’t go about this alone. If you are interested in finding out more about the risks and benefits, then talk to your doctor or dietitian.
So should the question be ‘what is the best diet for PCOS and weight loss’?
Managing PMOS/PCOS is about more than just “willpower” - it is about addressing a complex hormonal condition with the right tools. Weight loss may be one piece of the puzzle, but it is never the whole story. Whether you choose to focus on lifestyle adjustments, explore clinical support through medication, or a combination of both, the goal is the same: working with your body rather than against it.
Remember, you aren’t “failing” if you need support. Between managing insulin resistance, managing strong food cravings, and navigating fertility, there is a lot to juggle. Focus on small, sustainable shifts that help you feel more in control of your energy and your health.
Not sure where to start?
If you’re nodding along to this, you don’t have to figure it out alone. You can book a free 15-minute enquiry callwith me, Claire Pettitt, specialist women’s health dietitian, to talk about your PCOS/fertility journey and next steps - no pressure, just a chance to ask questions about 1:1 support and explore your options.