Hormone Health, The Wild Collective

The Most Common Cause of Weight Gain

Weight gain and loss isn’t always a matter of “calories in, calories out” – our bodies are far more nuanced and complex than this simple equation suggests. 

If you’ve felt frustrated by someone telling you to eat less and exercise/move your body more (because you’re already doing just that and not seeing the results), you’re certainly not alone. Keep reading to learn about how hormones play a role in your overall body composition. 

When it comes to weight management, many people have heard the fundamental concept’ “calories in, calories out” which tells us that: 

A. If you consistently consume more calories than your body expends, there is an energy surplus, and the excess calories are stored as fat and weight gain ensues. 

B. If you consistently expend more calories than you consume, creating an energy deficit, your body taps into its fat stores to make up for the deficit, leading to weight loss.

However, it’s important to note that the human body’s energy balance is influenced by various factors, including basal metabolic rate (the energy required for basic bodily functions at rest), physical activity, genetics, hormonal factors, and the type of foods consumed (it’s not just about calories). 

While the concept of “calories in, calories out” provides a foundational understanding of weight management, it’s just one piece of a complex puzzle that involves a variety of physiological and behavioural factors.

One of the most common causes of abdominal weight gain is actually insulin resistance (IR). 

IR is when the body’s cells do not respond effectively to insulin. When someone is insulin resistant, their cells can not turn sugar into energy properly so it gets stored as fat instead. This causes symptoms like lower energy, inflammation, and belly fat.

It’s important to know that you can have insulin resistance even if your doctor explained to you that your blood sugar testing came back normal. 

Insulin resistance is synonymous with pre-diabetes, “hyperinsulinemia” (high insulin), and is the underlying cause of metabolic syndrome. Research shows that those 20 years of age today face a 50% chance of developing diabetes in their lifetime. 

This isn’t just about weight gain or weight loss resistance; IR is associated with an increased risk of several serious health conditions including heart disease, high blood pressure, high cholesterol, cancer, and dementia. If you’ve been told you have fatty liver, there is a high likelihood you have insulin resistance. 

For women, insulin resistance could play a major role in:

  • PCOS, 
  • weight gain in perimenopause, 
  • heavy periods
  • osteoporosis.

If you were to ‘look up’ physical signs of insulin resistance you’ll see symptoms like 

  • abdominal weight gain
  • acanthosis nigricans (darkening of the skin in the armpits and neck)
  • skin tags or slow wound healing. Most people I see with insulin resistance do not have these physical signs. 

So, how do you know if you’re insulin resistant?

Conventionally in Canada, fasting blood sugar and HbA1C (3 month marker of blood sugar) is used. But other tests can gleam (but not diagnose) whether insulin resistance is present, such as seeing high triglycerides or cholesterol on a lipid panel. We may also see elevated inflammation markers such as C-reactive protein (CRP) or high liver enzymes. 

Your fasting glucose and HbA1C may register high, but often in mild-moderate insulin resistance, these remain within the normal range. This means that insulin resistance can be missed when only using these 2 blood tests.

Your other choice, test insulin itself.

Typically we use the HOMA-IR score or index which is a ratio of your fasted insulin and fasted glucose. 

Now for the good news!  Insulin resistance is reversible!

As insulin sensitivity improves, and high insulin levels begin to drop, your metabolism can be restored and weight loss can begin again. Abdominal weight will be very difficult to lose until insulin is back in the healthy range. 

This can take time; your metabolism can be healing for a while before weight loss starts. So don’t get discouraged! Tracking fasting insulin helps us re-assess and see improvements in insulin resistance even when you feel things are slow (or nil) on the weight loss front.

Here’s how you can improve insulin resistance:

  • Move your body to build muscle.
  • Adequate protein intake (I see women really struggle with this one).
  • Avoid ultra-processed “food-like” products.
  • Work on improving or restoring your circadian rhythms. Disrupted circadian rhythms are a risk factor or insulin resistance (think sleep-wake cycle, fasting-feeding cycle). Ways to work on this:
    • Consistent sleep-wake times.
    • Morning light exposure.
    • Food timing – eating your meals at the same time each day. 
    • ‘Time-restricted eating’, which, unlike intermittent fasting, does not restrict calories. E.g. eat normally during an 8- to 12-hour daytime window and fast during the remaining 12 to 16 hours, mostly overnight.
  • Food frequency – going 4-6 hours between meals (this can take time to get accustomed to and your meals have to be on point for this to be successful). In general, avoid grazing & cut (unnecessary) snacking. The most satiating macronutrient is protein so make sure you’re getting enough of it, plus veggies, and healthy fats yp help you stay satiated between meals. 
  • Avoid overeating.
  • A low-carb nutrition plan, for more advanced cases of insulin resistance.
  • Gentle intermittent fasting, for some cases.
  • Fix your gut. Inflammation from the gut can worsen insulin resistance. Do not ignore this one!
  • Get adequate sleep and rest. 
  • Reduce stress and engage in activities that get you into a parasympathetic state such as: light exercise, nature walks, breathwork, meditation, yoga/pilates, massage, etc.
  • Sex hormone balance – healthy estrogen, progesterone, and testosterone levels. Low testosterone in men can contribute to insulin resistance while in women the opposite is true, high testosterone can contribute to insulin resistance.
  • Supplements – there are many but a few include magnesium, myo-inositol, and berberine.

Want to learn more? Module 9 of the Wild Collective is all about blood sugar balance! I’ll be running this women’s group program again this Fall, if you’re interested, check it out HERE.

- Dr. Willow

  1. […] all this, I still see insulin resistance as the #1 reason for weight gain and difficulty losing […]

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I help women achieve optimal digestive and hormonal wellness through a root cause, individualized approach to medicine that utilizes functional lab testing, diet and lifestyle modification, nutritional and herbal medicine, and acupuncture to re-establish lasting health.


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Between my wait listed practice, building my Wild Collective communities, and being Mom, I don't email often, but I'm working behind the scenes to bring you major value and I'd love to be able to tell you about it when it is ready (along with some more personal shares).