A new year is with us and pretty much everyone I know has “lose weight” at the top of their list of New Year’s Resolutions, usually accompanied by the exclamation “I NEED to lose weight!”.

Medical science has uncovered the myriad ways in which being overweight or obese can harm our health.

But there is a difference between needing to lose weight to improve your health, and wanting to lose weight to fit some arbitrary aesthetic ideal. The former I support wholeheartedly. The latter, not so much. Let’s break it down.

There are only two circumstances in which you actually NEED to lose weight:

1. Where a registered medical practitioner, such as your family doctor, or an endocrinologist, cardiologist, orthopaedic surgeon or other medical specialist has advised you that losing weight will improve your health.

If you have any of the following health problems, I recommend you ask your family doctor or medical specialist if weight loss might improve your condition:

Type 2 diabetes
Joint problems
Sleep apnea
Hypertension
Elevated cholesterol or triglycerides.

Many of the above chronic health conditions are caused or exacerbated by excess weight, and weight loss has been shown in peer-reviewed scientific studies to reduce symptoms, boost wellbeing and extend lifespan.

2. Where your waist measurement or body fat percentage places you at risk.

Notice I didn’t tell you to get on a scale and weigh yourself?

This is because the scale just measures how heavy you are. It doesn’t distinguish between fat mass, lean muscle mass or healthy bone mass. Muscle and dense healthy bones actually weigh a lot more than fat, and your waist measurement provides a far more meaningful assessment of any weight-associated health risks than a number on a scale.

I also didn’t mention BMI…

Body Mass Index (BMI) is a great tool for assessing health and chronic disease risk at the population level. But it’s quite clumsy and can be inaccurate when used to assess individuals. Because it uses body weight as measured by a scale, it doesn’t distinguish between fat mass, lean muscle mass or healthy bone mass. So it can give false negatives and false positives in cases such as super-fit, muscular athletes who are classified as “obese” due to the fact that muscle weighs more than fat, whilst frail older women with sarcopenia obesity* are classified as having a healthy BMI.

Experts recommend focussing on waist measurement because fat that accumulates around our waist (also known as Visceral Adipose Tissue or “toxic fat”) is considered a strong predictor for risk of type 2 diabetes, cardiovascular disease, stroke and even some types of cancer!

So here’s what you can do:

1. Measure your waist: It is recommended that women keep their waist circumference below 80cm, and men keep theirs below 94cm.

2. Calculate your waist-to-hip ratio: It is recommended that women have a ration of <0.8 and men <0.9.

3. Check your waist-to-height ratio: It is recommended to keep your waist measurement to less than half your height to reduce your disease risk.

4. If you want to get a deeper picture of your health and wellbeing consider having a DEXA scan done. A DEXA scan is a type of low-level x-ray that can show your body composition - the amount and location of your body fat, lean body mass, and even the density of your bones! They are not cheap, at around $150 per session, but they are considered the “gold standard” method for assessing body composition, and can be incredibly helpful if you want to track changes in body composition over time. DEXA scans an be especially helpful in identifying whether you have visceral adipose tissue (or VAT), sometimes referred to as “toxic fat” as it sits within organs and tissues where it doesn’t belong and where it can wreak metabolic havoc. If you do have VAT and commit to healthy nutrition and lifestyle changes, it can be very satisfying and motivating to see that awful VAT diminish from scan to scan!

So if neither of the above two reasons to lose weight apply to you, then you don’t NEED to lose weight, you WANT to lose weight.

And if you WANT to lose weight for reasons that are not associated with your health, then I highly recommend you block out a bit of quiet time and ask yourself exactly why it is that you want to lose weight - how do you think your life will change? What has influenced your decision?

Obesity has significant adverse health impacts. Having jiggly thighs does not.

I’m getting so very tired of coming across amazing women who are making themselves miserable, depriving themselves on unsustainably restrictive diets and pushing themselves into nutritional deficiencies when they have absolutely no need to do so, and are just buying into some BS artificial construct of what they “should” look like, believing that doing so will miraculously improve their self-esteem, lovability and happiness.**

But if your doctor has advised you that losing weight is likely to improve your health, if your waist measurement places you into the “at risk” category or if your DEXA scan indicates Visceral Adipose Tissue (aka “toxic fat”), then yes, I’m all in favour of you making simple, healthy, sustainable changes to boost your health and lose weight.

Notice I didn’t use any “D-words” - I didn’t say diet, I didn’t imply deprivation, and I don’t recommend any earth-shattering drastic changes.

If you do genuinely need to lose weight to boost your health and wellbeing, I want you to take a “health-first” approach to weight loss - boost yourself up your list of priorities and make your health and longevity a priority. By moving more, by eating more veggies, by getting enough sleep. And by enlisting the help of your doctor, a coach, a nutritionist, a (genuinely) supportive friend or even a psychologist.

I really wish we could all take the focus off weight and put that focus onto the daily choices we make in relation to our nutrition and lifestyle. That’s because no matter what we weigh, we can all benefit from taking steps to improve our nutrition and lifestyle.

And in an ideal world, we would all just prioritise healthier choices each day, and in doing so it is likely that if we are carrying excess weight it will reduce over time without any painful “weight loss efforts” on our part.

***

* Sarcopenic obesity is a combination of obesity and the muscle wastage that is often seen in the elderly.

** Trust me, it won’t.

REFERENCES

Ashwell M, Gunn P, Gibson S. Waist‐to‐height ratio is a better screening tool than waist circumference and BMI for adult cardiometabolic risk factors: systematic review and meta‐analysis. Obesity reviews. 2012 Mar 1;13(3):275-86.

Cameron AJ, Magliano DJ, Söderberg S. A systematic review of the impact of including both waist and hip circumference in risk models for cardiovascular diseases, diabetes and mortality. Obesity Reviews. 2013 Jan 1;14(1):86-94.

Ashwell M, Gibson S. A proposal for a primary screening tool:Keep your waist circumference to less than half your height’. BMC medicine. 2014 Nov 7;12(1):1.

Ashwell M, Gibson S. Waist-to-height ratio as an indicator of ‘early health risk’: simpler and more predictive than using a ‘matrix’ based on BMI and waist circumference. BMJ open. 2016 Mar 1;6(3):e010159.

Zhang YX, Zhao JS, Chu ZH. Waist to sitting height ratio may be a new useful index for screening obesity and related health risk. International journal of cardiology. 2015 May 6;187:126-7.

Ashwell, Margaret, and Sigrid Gibson. "A proposal for a primary screening tool:Keep your waist circumference to less than half your height’." BMC medicine 12.1 (2014): 1.

Saltiel, A.R. and Olefsky, J.M., 2017. Inflammatory mechanisms linking obesity and metabolic disease. The Journal of clinical investigation, 127(1), pp.1-4.

Williams, E.P., Mesidor, M., Winters, K., Dubbert, P.M. and Wyatt, S.B., 2015. Overweight and obesity: prevalence, consequences, and causes of a growing public health problem. Current obesity reports, 4(3), pp.363-370.

GBD 2015 Obesity Collaborators, 2017. Health effects of overweight and obesity in 195 countries over 25 years. New England Journal of Medicine, 377(1), pp.13-27.