In part one we looked at how fat is distributed and why it matters, the functions of fat, and the challenges losing abdominal fat. If you haven’t yet read it, we strongly encourage you to do so as it will help to put part two into perspective.
In part two we’re going to look at whether cortisol influences abdominal fat, how to measure body fat and the potential limitations thereof, and we’re going to addressa few common misconceptions.
To reiterate what we said at the beginning of part one. At GF Fitness we always want to remain objective and base our content on facts; this post includes a fair amount of information from respected and trusted sources, and we deem everything we’ve included necessary for the purpose of this post.
Does cortisol influence abdominal fat?
Most of us are aware of the role stress can play in adversely affecting our health. Stress causes the body to release cortisol:
“… cortisol makes energy available in your bloodstream in the form of glucose. That’s helpful if you’re a cave person who needs to flee a predator, but if work deadlines or bills cause your stress, the result will often be fat, stored in your belly. This is because cortisol affects where fat is stored. People with elevated cortisol store fat centrally,around their organs. Stress also causes many people to overeat, exercise less and sleep less … The study “Low Calorie Dieting Increases Cortisol” revealed that cortisol levels in dieters’ saliva showed the act of restricting calories led to a stress response. “It’s not just that people should try to avoid stress while dieting,” Mann wrote. “It’s that stress cannot be avoided when you are dieting, because dieting itself causes stress. Dieting causes the stress response that has already been shown to lead to weight gain”.
After a recent weigh-in by John (actual name has been changed), his third over the past 6 months, we noticed a trend beginning to emerge – his body fat percentage was steadily creeping up, and his waist circumference measurements were also on the rise. John had been exercising with us as per his usual routine, following his regular diet, and keeping an accurate food diary; he was seemingly doing all the right things. After further discussion, John shared that over the past six months he’d been immensely stressed since he lost a huge corporate client. In turn, the stress of the situation led him to sporadic binging on M&M’s and more wine than usual. Two things to note: firstly, his stress led him to develop a bad habit of binge eating and drinking. Secondly, even though his regular exercise routine hadn’t changed, and his food diary, for the most part, indicated good nutritional habits, his cortisol levels were still likely to be elevated throughout this period.
What can we learn from John? With regards to exercise and nutrition, we could seemingly be doing all the right things, but an elevated cortisol level could negate all our efforts. The way stress manifests itself is dependent on the individual; for some it could lead to binge eating, which once off is normal, but it’s the bad habit that we want to stop from developing. Exercise and nutrition are incredibly important, but they cannot be isolated, and that’s why we advocate a holistic approach; we need to know things such as changes in sleeping patterns, significant life events, a relationship that may be going through a rough patch – all potential stressors that could lead to an elevated level of cortisol.
Measuring body fat
Before we take a look at how to measure body fat, it’s important to be aware of and understand it’s potential limitations.
Firstly, most methods for measuring body fat are widely inaccurate.
Tony Leyland on measuring body fat, “In short, fat in the body is found around nerve cells, in the blood (lipoproteins and triglycerides), in cell membranes, within our organs, deep in the torso, in subcutaneous adipose tissue, etc. Clearly it is not an easy thing to measure, and even underwater weighing, often considered the gold standard test, is not that accurate. If you get a body composition test done and you are told your percent body fat is, for example, “12%,” you are being given only part of the results. The accurate information would be something like “12% body fat with a standard error of estimate of 3%.” What that means is that approximately two-thirds of the people getting this result would actually be between 9% and 15% body fat. The other third would be outside this range. About 95% of the population would be between 6% and 18% body fat with 5% of people outside even this range … Because no single body composition tool is ideal, the best scenario is to use a combination of simple measures.”
Secondly, body fat percentage should be cautiously noted regarding our overall health.
“Health is about physiology; it is about how efficiently the cardiovascular system pumps blood and how the pressure within the arterial walls is regulated, how fats are transported in the bloodstream, how the body moves oxygen and nutrients into tissues across cell membranes, how it moves carbon dioxide and waste products out of the tissues, how waste products are filtered, etc. … Thinking about health in terms of these types of physiological parameters makes sense; trying (ineffectually) to estimate how much body fat you have doesn’t … I am not ignoring the large body of epidemiological data that has documented the association between obesity and numerous adverse health consequences including a spectrum of metabolic and cardiovascular disorders. I have read a lot of it. But correlation is not causation, and there is an emerging set of research that questions “obesity” as a health risk. Increasing evidence suggests that obesity is not the causative health problem but that factors such as poor diets, inactive lifestyles, weight cycling (yo-yo weight loss and gain) are.”
Thirdly, body fat is not a good indicator of fitness.
“A “good” body fat percentage is not necessarily a marker of fitness either. Go to a party full of serious marathon runners (with really low percent body fat) and the topic of conversation will be their latest injury and/ or upper respiratory tract infection. And professional bodybuilders who pack unnaturally large amounts of muscle onto their frames and maintain very low percent body fat have what many would consider “excellent” body composition, but their performance on many of the components of fitness would be dismal. What I am arguing is that we should always focus on performance (at the whole human and cellular level). If one … athlete has 7% body fat (let us imagine for the moment that we could measure it accurately) and another 10%, who is the fitter?”
A magnetic resonance imaging (MRI) study or CT scan are currently considered the gold standards for measuring visceral and abdominal fat, but both are relatively impractical and expensive. Bioelectrical impedance scales are less accurate but more widely available. If none of those are options available to you, a simple technique is to simply measure your waist circumference.
According to the NHS:
“Regardless of your height or body mass index (BMI), you should try to lose weight if your waist is:
. 94cm (37in) or more for men
. 80cm (31.5in) or more for women
You’re at very high risk of some serious health conditions and should see a GP if your waist is:
. 102cm (40in) or more for men
. 88cm (34.5in) or more for women”
Another option to consider is your waist to height ratio. According to Dr. Bret Scher, MD, “Keeping your waist-to-height ratio below 0.5 may be an even better measurement [than waist circumference alone] for predicting a lower risk of health complications.”
Low Risk: <0.5
Intermediate Risk: 0.5 – 0.6
High Risk: >0.6
To calculate your waist-to-height ratio simply divide your waist circumference by your height e.g., somebody with a waist circumference of 84cm and a height of 168cm would have a waist-to-height ratio of 0.5.
Measuring our bodyweight is simply one of the many indicators we can use to assess our health. Regardless of its limitations, we believe it offers valuable insight, it should be regularly measured, but it should not be used as the sole assessment of our overall health.
We’re now well aware that that visceral fat is essential, but in excess it could pose serious health risks. Our desire to lose abdominal fat may cloud our judgement, or smart marketers may take advantage of this desire, therefore, we want to share some common misconceptions.
“One common misconception is that doing stomach strengthening exercises, like crunches or sit-ups, helps people lose belly fat. But studies show that sit-ups alone are not effective at reducing belly fat … Other types of exercise, especially when combined with an effective diet, may reduce belly fat. For instance, two trials reported high-resistance training and moderate-cardio programs had a greater impact on belly fat loss than lower-intensity exercise … Aerobic training alone may also be effective for visceral fat loss, but the key seems to be the intensity. Only studies of moderate and high-intensity aerobic exercise find a meaningful impact on belly fat.”
“A randomized study reported that those supplementing with Lactobacillus amylovorus experienced a small decrease in abdominal fat compared to those eating yogurt made with other bacterial strains. However, there’s still much to learn about our gut flora’s impact on weight loss and body composition. The evidence is not strong enough to make a general recommendation about using probiotics to lose belly fat. But, if you choose to take probiotics for other reasons, you may want to consider strains with Lactobacillus amylovorus.”
Apple cider vinegar:
“One study in Japanese men reported those who drank 0.5 to 1.0 ounces (15 or 30 ml) of vinegar decreased their waist size by about 0.5 inches in 12-weeks … Again, the evidence isn’t likely to be strong enough to recommend vinegar specifically for belly-fat loss. But if you are taking it for other reasons, you might see a small benefit.”
Marketing for most supplements tend to overstate their potential benefits to help people lose abdominal fat. Although the evidence is limited, some people may see a small effect from probiotics or apple cider vinegar. Remember, a supplement should be exactly that, a supplement. They should not be seen as a substitute or remedy for a diet consisting of junk, processed foods. They may, however, accompany a diet consisting of real, whole foods. In our opinion, when it comes to body fat loss, there’s no substitute for sound nutrition; you can read about our approach to nutrition here. If we’re able to reduce our overall body fat, it’s likely that any excess abdominal fat will follow suit.
Thank you for reading this post
We truly hope that you found part one valuable. If you have any questions or if you’d like to work with one of our experienced personal trainers, please feel free to contact us
‘Fat, Part 1: Anatomical Distribution’, CrossFit, 17 July 2020. Available at: https://www.crossfit.com/essentials/fat-part-1-gross-anatomy. (Accessed: 20 February 2021).
Scher, B. (2021) ‘How to lose belly fat’, Diet Doctor, 17 February. Available at: https://www.dietdoctor.com/how-to-lose-weight/belly-fat. (Accessed: 20 February 2021).
Achauer, H. (2016) ‘Restricted Success’, CrossFit, 8 December. Available at: https://journal.crossfit.com/article/restricted-success-2. (Accessed: 20 February 2021).
Leyland, T. (2007) ‘Body Composition’, CrossFit Journal, January. Available at: http://library.crossfit.com/premium/pdf/53_07_Body_Composition1.pdf?e=1612514749&h=8535f69fec308c946b91e8334f7ea0e3&_ga=2.183897893.248235833.1613295721-1855502418.1613295721. (Accessed: 20 February 2021).
‘Why is my waist size important?’, NHS, 24 September 2019. Available at: https://www.nhs.uk/common-health-questions/lifestyle/why-is-my-waist-size-important. (Accessed: 20 February 2021).