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00:11
Hey everyone, it's Mikki here. You're listening to another Mini Mikkipedia on a Monday. And this Monday, I wanna talk about belly fat and the role of hormones, lifestyle, as contributing factors, and also what we might be able to do to reduce belly fat. And this is something which I get quite a lot, particularly because it's quite well known that as we age,

00:38
particularly women, we tend to store more fat around the middle than we do around our thighs and our butt, which is generally the sort of storage pattern that occurs over our sort of reproductive years, sort of post puberty. Women are much more likely to store their fat around their hips, around their thighs,

01:06
subsequent childbirth and reproduction, et cetera. When our hormones change, as we go into perimenopause, the deposition of fat also changes, but it is more than just the change in sex hormones. And so I wanna talk about the hormone changes that occur that are associated with an increase in fat storage around the middle, and also...

01:31
Other things that occur as we age that contributes to increasing sort of waist circumference and out of all of the health indicators, your waist circumference is a big one when it comes to risk reduction and getting your waist in centimeters or inches to be half your height or below is a really good.

01:57
easy to measure marker that indicates a reduced risk for cardiovascular disease, for type 2 diabetes and other metabolic disorders. However, let's go through some of these changes in hormone levels. So the first thing is obviously hormone levels change and as I said, menopause does lead to this decrease in estrogen which can cause fat redistribution from the hips and thighs to the abdominal region.

02:26
And you know, for some women, this is really new to them. They've never had to worry about their waist before and then suddenly they're gaining weight. And in addition to this, you do get an almost shift in the phenotype or how the body looks as well. And we can lose muscle in our limbs. So our arms and our legs, they can appear really skinny. Our butt can sort of lose its shape and go sort of pancake flat. And then we just get this sort of more apple storage. Sorry.

02:55
apple shape if you like rather than the pear shape if you are familiar with those descriptions of body size which I sort of grew up in, we learnt about in nutrition and all that sort of thing. And it's not just women that experience this sort of increasing belly fat as well related to hormonal changes, men experience a decline in testosterone levels which can also contribute to increase abdominal fat. But it's more than just these hormones here. Now we're well familiar with

03:24
the relationship between stress and increasing cortisol and fat storage around the middle. So cortisol is produced by the adrenal glands and is called the stress hormone. And under acute stress conditions, cortisol levels increase and with it, they increase glucose in the bloodstream and enhance brain sugar uptake. And this is an adaptive response. However, chronic stress leads to these prolonged elevated levels of cortisol.

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which can increase appetite and drive cravings for sugary and fatty foods, leading to increased calorie intake. Cortisol also promotes fat storage in the abdominal region. And this is actually really well studied. So like just as an example, there was one study that I came across, which was a study just looking at waste circumference and stress levels.

04:21
and looked at women who were already overweight that did in fact have a high waist to hip ratio, which is an older marker of metabolic health if you like, looking at your ratio between waist and hip. A low waist to hip ratio indicates better health, a high waist to hip ratio indicates poorer health. And they looked at this in relation to their salivary cortisol response to stress. Now, salivary cortisol isn't an excellent marker for

04:50
for stress levels, but it's really well used in literature, so it can be quite a good barometer. Women with a high waist to hip ratio secreted more cortisol in response to stress than those with a low waist to hip ratio, especially after prolonged stress exposure. So this indicates that not only does high stress increase visceral fat deposition, so fat around the middle, but actually having increased fat around the middle can...

05:19
further sort of exacerbate that stress response. So these can sort of perpetuate each other if you like. And interestingly as well, there was when they looked at anger levels in amongst of these women, the woman with the higher stress response showed a decreased level sort of anger. So they didn't appear as angry under certain conditions as women who had lower waist to hip ratio and lower stress response. And it almost sort of suggested that

05:47
These women who had this like high stress response were really able to control their emotions on the outside, but it was what was going on on the inside that really made a difference to that stress response, which is why you cannot always tell how a sort of the stress response of someone just by sort of going on how they may respond in a certain situation because you don't always know sort of what's going on underneath if you like. So you know, while that study focused on waist to hip ratio in overweight women,

06:16
The broader field looking at stress and waist circumference or fat deposition has explored that relationship in various populations. Some notable findings from this is that chronic stress is associated with prolonged cortisol secretion and that stress response which is regulated by our hypothalamic-pituitary-adrenal

06:43
And in acute situations, it's adaptive, as I said before, but chronic stress leads to these consistently elevated cortisol levels. We know that cortisol promotes lipid accumulation in visceral fat cells, and those visceral fat cells is the fat surrounding internal organs. Its accumulation is more detrimental than subcutaneous, or fat just beneath the skin. Several studies have shown that individuals with higher visceral fat have a heightened cortisol response to stress.

07:12
can lead to changes in eating behaviors, which can result in those increased consumption of high calorie, high fat, or high sugar foods. As I mentioned earlier, this enhances the appetite and cravings for these foods, and this can contribute to belly fat accumulation. And also chronic stress can disrupt sleep patterns. And in turn, this poor sleep can elevate cortisol levels and promote fat storage in the abdomen region.

07:41
Several studies have shown there is a correlation between sleep deprivation, increased cortisol, and weight gain. There is of course individual variation in some an individual's response to stress based on genetics, environment, and individual experience, and therefore perception of stress. And some individuals might be more resilient, or others might be more vulnerable to its effects.

08:06
Studies have found that individuals who perceive their lives as stressful or have depressive symptoms have higher cortisol levels and more abdominal fat than those who don't. And of course, social support and effective coping strategies can potentially buffer some of these negative effects of stress on cortisol and fat distribution. Aging can alter the HPA axis of responsiveness, leading to changes in cortisol secretion patterns, which, combined with other age-related factors that I'll talk about,

08:34
might contribute to an increased abdominal fat in older adults. And high cortisol levels and increased abdominal fat are also associated with metabolic disturbances like insulin resistance and cardiovascular diseases. So there is quite a strong link in the literature and clinically between stress, cortisol, and abdominal fat. So when we're thinking about hormones most associated with abdominal fat and fat storage around the middle, it's no...

09:03
surprise that cortisol is one of the first things that is mentioned, or one of the first hormones that is mentioned outside of the sex hormone sort of changes as we age. But it's not just cortisol and estrogen and testosterone. Insulin, which is actually intricately tied to all of these. So insulin as a reminder is produced by the pancreas. It regulates glucose metabolism and nutrient storage. And when there's an excess intake of carbohydrates,

09:31
body releases more insulin to help use or store the glucose and other nutrients like fatty acids. Elevated insulin levels promote fat storage and can inhibit fat burning. And over time, with consistent excessive carbohydrate consumption, the body may develop insulin resistance where cells no longer respond effectively to insulin. And this situation can lead to more fat storage in the abdominal region.

09:58
fatty liver disease, and increased risk for type 2 diabetes. And also, if we go back to cortisol, cortisol can elicit this insulin response in that stress situation as well. So this certainly comes into it. So we mentioned estrogen and estrogen's role in sort of fat distribution. Testosterone is primarily produced in the testes in men and smaller amounts in the ovaries in women. And testosterone helps in muscle development and fat burning.

10:26
With age, especially in men, testosterone levels decline, which leads to a decrease in muscle mass and an increased fat accumulation. However, this is the same with women as well, and it's not often discussed, is that we understand about estrogen roles sort of fluctuating all over perimenopause, then sort of headed out. We understand that prodesterone takes a sort of more slow decline in the background.

10:53
but testosterone does the same thing. And because of testosterone's role in helping us increase sort of strength gains and muscle mass, when we lose testosterone, we also lose motivation and drive, we drop muscle mass, and this just increases our ability to store fat around the middle. Now ghrelin, ghrelin you're probably familiar with, it's produced in the stomach, and it's an appetite or hunger hormone it's described as. So it signals to the brain that it's time to eat.

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Elevated levels of ghrelin can lead to increased food intake, and sleep deprivation and certain dietary choices do increase these ghrelin levels, which can contribute to weight gain. Oftentimes we hear or we talk about ghrelin, but there's also leptin, which is produced by fat cells. And leptin signals the brain about the amount of stored fat and regulates appetite. As individuals gain weight, their fat cells produce more leptin, however prolonged leptin

11:52
elevated leptin levels can lead to leptin resistance, not unlike insulin resistance, where the brain no longer responds effectively to those leptin signals. So this can lead to an increased food intake and decreased energy expenditure. So leptin's job really is to tell us when we're full. However, if you've got that resistance or leptin resistance, you lose that signal. And this is when

12:18
you can't sort of distinguish when you are hungry or when you have been satisfied. And another hormone which we are less familiar with, or at least sort of in the social media space, is adiponectin. And this is also produced by fat cells. And adiponectin enhances the body's ability to use carbohydrates for energy and boosts metabolism. And it's a marker that's often sort of studied in exercise science. It also has anti-inflammatory effects.

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lower levels of adiponectin are associated with increased abdominal fat and insulin resistance. So adiponectin is an adipocyte, which is fat cell-derived hormone with anti-inflammatory properties and beneficial effects on glucose and lipid metabolism. So while it's produced by fat cells, paradoxically, it tends to be lower in individuals with higher amounts of body fat, particularly fat around the middle or that visceral fat.

13:16
And there are several factors and conditions which can lead to decreased adiponectin levels. So obesity is one, which I just mentioned. Insulin resistance and type 2 diabetes, they tend to have lower adiponectin levels. And adiponectin enhances insulin sensitivity and lower levels can further contribute to that worsening glucose regulation. There is also evidence that suggests adiponectin levels decrease with age, even after adjusting for body fat percentage and other factors.

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It's unsure at this point in time what that exact mechanism is, but it might involve sort of various changes in adipose tissue function and distribution with age. Sex plays a role and men typically have lower adiponectin levels than women, and it's believed to be partially influenced by testosterone, which can reduce adiponectin secretion. And then chronic inflammation can suppress adiponectin production.

14:15
often sort of coincides with these reduced adiponectin levels. So you see, these are actually really interlinked. Certain dietary patterns as well, like diet which is high in, has a high omega-6 to omega-3 ratio can reduce adiponectin levels. And conversely, a focus on omega-3 fats which sort of change that ratio of omega-6.

14:43
which is like your linoleic acid and things like that. Changing those levels and boosting omega-3 from things like salmon, sardines, mackerel, and fish oil supplements or blue algae supplements may increase adiponectin levels by changing that ratio of omega-6 to omega-3. It could just be genetics. Your adiponectin levels might just be what you were born with. And then there are some medications which influence adiponectin levels.

15:10
Now I just wanted to sort of highlight this because, you know, it's so easy to go to some of the hormones that we know to be like an issue and think, oh, it's got to be a problem with my estrogen. It must be that, you know, I've got high cortisol, but it can be other things in the mix as well. And this is not something you necessarily get measured, but it's just good to be aware of it. And then the strategies to help reduce belly fat will all help bring these other markers into line.

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and particularly because of adiponectin's role as an anti-inflammatory molecule, a re-establishing that sort of better baseline health can occur when you reduce your belly fat levels. Anyway, what are some other factors outside of those hormones which I just went through that impact on belly fat? So well, we've got decreased muscle mass and that came up a little bit in relation to testosterone. I didn't mention it with estrogen, but that's another one as well.

16:07
Starting in our 30s, we can lose 3-5% of our muscle mass each decade due to age-related sarcopenia. And I spoke to Professor Brendan Egan about this at length in a podcast looking at aging and sarcopenia. Because muscle burns more calories than fat, a decrease in muscle mass can slow down metabolic rate slightly, making it easier to gain weight. But also, if we think about the

16:37
reduce muscle mass and increase fat mass, like it changes the function of those fat cells as well. And a dysfunctional fat cell that isn't working as well due to inflammation, reduced adiponectin, high levels of cortisol, reduced muscle mass, are also gonna have implications for that continual sort of visceral fat gain. Let's not forget that it could just be lifestyle changes. You know, like you're just not as active as you get older. You...

17:05
might think that you run around a lot with your kids but suddenly they're 15 and you're not running around after them anymore. Changes in our work schedule, demands related to being either part of our career or being carer for older parents. This changes our free time or our perceived time that we have to

17:26
ensure we're doing things that are really good for our health like being physically active and food prepping and stuff like that. So lifestyle changes can definitely impact on muscle loss, weight gain and belly fat gain. It goes without saying that a poor diet, all the things that I've mentioned with high calories, poor nutrients, high refined carbohydrate are all going to impact on how much fat you store around your middle and on your body. Insulin sensitivity we've already talked about.

17:54
Genetics as well, you know, like if you look at your grandparents and your parents and they tend to sort of store more fat around the middle You're more predisposed to doing that do note However, that doesn't mean that it's you know a done deal There are plenty of things you can do to reduce the belly fat poor sleep always comes up and for good reason Because it's linked to insulin resistance higher cortisol lower testosterone and

18:22
The hormones, these hormones of course, our hunger hormones, these all impact our food choices and our fat storage and other health conditions. So certain medical conditions and medications can promote weight gain or changes in fat distribution. So there are like plenty of reasons as to why our body shape changes over time, but as I said, it's not inevitable. So what are some of the things?

18:49
that we can do to help reduce the likelihood of belly fat or to reverse some of the changes that have occurred. Now, depending on your diet, I would obviously start with a higher protein diet, the way that I always talk about. Focusing on reducing body fat, improving body composition, even if you are of a normal or a healthy weight according to say,

19:18
you know, BMI, which always has its limitations. And I know that you know that, but really starting with thinking about your body composition, I think is the first thing, because the more you're able to shift your body shape to carry more muscle, to reduce sort of body fat, then that's gonna have major implications for belly fat storage and your overall health. And in fact, you shouldn't even, particularly people who don't necessarily, aren't necessarily overweight,

19:48
You should just focus on building muscle and body composition. You shouldn't focus about losing weight actually because losing weight you run the risk of putting into place strategies that will further accelerate that muscle mass loss which is exactly what you don't want. So instead focus on the activities that help build muscle as you age. Darren and I spoke

20:11
at length about what these are a couple of podcasts ago. So definitely go back and check that podcast. I'll put a link in the show notes to that. Ted Naiman and I also discussed diet in relation to sort of muscle mass, overall health, belly fat, personal fat threshold, things like that. So go back and listen to Ted Naiman's podcast, a wealth of information. I'll pop a link in the show notes to that. And remember, you know,

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Gabriel Lyon and Professor Don Lehman talk about muscle centric medicine and we're not over fat, we are under muscled. So do bear that in mind. And of course, if you are carrying excess body weight and excess body fat and are with obesity, then an active campaign to lose weight does make sense. And the podcast which I just mentioned will all help give you some

21:04
clarity around what that diet can look like. And of course, you know that I have fat loss plans as well. Stress management is huge. And I cannot overstate how important it is if you have excess belly fat around your middle. There is just such a strong link between that cortisol and the accumulation of adipose tissue around the middle. So the more that you can manage your stress, the better you're going to be. Now,

21:32
For some of us who are active people, we often manage stress by going for a run or doing some HIIT training and things like that. And whilst these things are great, you just have to remember that it's constantly taxing that sympathetic nervous system. And what you actually need is to take your foot off the accelerator and engage in activities that help engage the parasympathetic nervous system, the rest and digest.

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So the stress levels can begin to come down, cortisol secretion can drop down, and your body gets more familiar with being in that parasympathetic nervous system state. And these are activities like journaling, like grounding, like cold showers, like sauna. But it's also, you know, diet really plays a role with the sympathetic slash parasympathetic nervous system state. So again, with

22:29
the vegetables that are high in phytonutrients and contain antioxidants. Breathing right through your diaphragm totally engages your parasympathetic nervous system in a heartbeat. Breathing through your nose increases nitric oxide, helps improve that vasodilation, helps just settle your whole nervous system down. Ensuring you've got adequate sleep. This is all part of sort of stress management, but again, it comes to that next sort of topic.

22:58
I spoke about the importance of sleep for night shift workers or shift workers last week, but just for all of us, we need to prioritize sleep and getting that eight hours in bed to ideally try and get at least seven hours sleep is really going to help significantly reduce stress but also help restore that hormone balance or imbalance that occurs when we have high stress

23:28
can be a really good way to reduce belly fat. And in fact, it's one of the most effective things. And I would say that there is absolutely room for a fasting protocol if you have a lot of excess fat to lose in general. If you're someone who is lean, yet carries belly fat, fasting wouldn't be the approach that I would take with you initially, actually. And I would look more to that sort of building muscle mass and building that strength and power first.

23:56
and regulating blood sugar through good food choices. But certainly fasting can be super effective. And if you've got your sort of blood sugar regulated, then even beginning with like a 10 hour eating window, having a 14 hour fast can really help improve your sort of body's response to fasting and help reduce that fat around the middle. And if you remember, I spoke to

24:24
Dr. Amy Goss, who is the assistant professor and researcher at the University of Alabama at Birmingham, all about her research looking at fatty liver disease, looking at visceral fat and the effects of a low carb diet. So from a nutritional standpoint, both fasting and a low carb diet can be super effective at reducing belly fat.

24:50
It absolutely makes sense to my mind that you limit the intake of refined carbohydrate in general though, and of course sugar sweetened beverages. And I also mentioned adiponectin and that increasing that omega 3, the amount of omega 3 in your diet through salmon, sardines, mackerel, even anchovies can help reduce that fat around the abdominal region.

25:20
and studies have shown that. Something which I didn't mention though, is the effects of probiotic foods or supplements. And researchers have found that different types of bacteria play a role in that weight regulation and that having the right balance of bacteria can help with weight loss, including belly fat. So there are some members of the Lactobacillus family, which is one of the most abundant sort of bacteria types in our gut.

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may well help reduce or enhance the impact of your weight loss approach with fat loss around the middle. Research is pretty new in that area, but it's certainly something to be considered. To summarize these things then, none of these strategies or interventions are particularly new or noteworthy outside of what we would already recommend when it comes to health,

26:19
reducing body fat in general. But I hope what you get from this that it is more than just cortisol, it is more than just estrogen. There are so many different sort of hormones related to the accumulation of belly fat and all of the lifestyle stuff that we discuss is also really important. So it's not that you have to do every single one of them but feel I think

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Hopeful if you're in this situation that there are many levers you can pull to get some results here Anyway, so these are my thoughts on why why belly fat sort of increases as we age and Also what we can do about it Let me know what you think catch me on Instagram Twitter and threads @mikkiwilliden on Facebook @mikkiwillidennutrition over on my website mikkiwilliden.com and

27:13
Book a call if you want to discuss it further. Alright guys, have a great week.