Natalie Lam, HK BioTek Intern
The previous article introduced the two-way interaction between hormonal imbalance and weight gain (NO PREVIOUS ARTICLE?), which forms a vicious cycle that exacerbates hormonal imbalance and weight gain. However, through strategies it is related to a person’s dietary habits, exercise habits, and handling of psychological stress, the vicious cycle can be terminated.
Strategy #1: Stick to the Mediterranean diet
Let me be frank - diet foods are often unpalatable, non-nutritive and unsatisfying. As a result, dieters tend to revert to their previous dietary habits, which is why their weight will rebound shortly after dieting.
If you would like to lose weight, you don’t have to obsessively count your caloric intake, because the Mediterranean diet (MD) can help you avoid the “nightmares” of dieting.
The Mediterranean Diet Centre show a lot of mouth-watering Mediterranean cuisine and the benefits for this diet are remarkable. It can help with heart and gut microbiota health. The MD encourages a high consumption of plant-based foods and omega-3 fatty acids (FAs). Both MD components not only make the food more palatable, nutritious and “filling” than diets that promise unreasonably rapid weight loss, but also exert positive influences on the composition of gut microbiota, which can potentially reverse diet-induced weight gain.
Plant-based components in the MD and weight loss
Plant-based foods in the MD, including plant proteins from soybeans and non-digestible carbohydrates from whole grains. They both act as prebiotics.
To put it simply, they act as food for beneficial gut microbiota in the large intestine. As these prebiotic plant-based compounds reach the large intestine, they are fermented by beneficial gut microbiota, such as Bifidobacterium and lactic acid bacteria. Energy and short-chain fatty acids (SCFAs) generated from fermented prebiotics are utilized for the growth of these beneficial microbiota. The newly formed beneficial microbiota not only produce antimicrobial substances that can kill off harmful gut microbes, but in turn also produce SCFAs.
All products yielded from the above 2-step reaction help rectify hormonal imbalance and hormonal imbalance-induced weight gain. In particular, three types of SCFAs, acetate, butyrate and propionate, act on hormone-secreting gut cells in the gut-brain axis, which signals the brain to stimulate their secretion of satiety hormones. As SCFAs on these gut cells also stimulate the release of brain chemicals that confer relaxing effects, which helps avoid a hyperactive hypothalamic-pituitary-adrenal (HPA) axis hence weight gain.
Omega-3 FAs in the MD and weight loss
In the MD, for example omega-3 FAs found in olive oil and oily fish for example should be consumed more frequently compared to omega-6 FAs that are found in sunflower oils for example. Omega-6 FAs are pro-inflammatory - which as previously mentioned, stimulates the secretion of stress hormone cortisol, appetite and therefore weight gain. In contrast, omega-3 FAs exert anti-inflammatory effects by acting as a prebiotic of beneficial gut microbes and suppressing the production of harmful gut microbes, resulting in an overall increase in SCFA concentrations.
Apart from encouraging the consumption of plant-based components and omega-3 PUFAs, the MD also recommends minimising the intake of animal proteins, saturated fats, processed food and high-sugar foods. Long-term consumption of the four food types results in a low Bacteroidetes-Firmicutes ratio. The Bacteroidetes-Firmicutes ratio is commonly used as a marker for gut microbiome changes in obesity research, as leaner and healthier individuals have more Bacteroidetes and less Firmicutes.
If you would like to restore hormonal balance and achieve weight loss, you may consider adapting to the MD for a prolonged time, since a low MD adherence is correlated with a lower Bacteroidetes-Firmicutes ratio.
Strategy #2 - Do regular moderate- or high-intensity aerobic exercise
It is indeed a challenge to get yourself moving regularly, but you should be aware of the 70/30 rule, in which 70% of successful weight loss lies on the foods you eat, while the remaining 30% depends on exercise.
Like the MD, regular moderate- or high-intensity aerobic exercise correlates with an increased Bacteroidetes-Firmicutes ratio and higher SCFA production. You may not know where to start from by just hearing the terms “moderate-” and “high-intensity”, so you may use the following conversion table as a reference:
It is perfectly fine if none of these exercises appeal to you, just pick your preferred sport and do make sure that it meets the criteria of a moderate- or high-intensity exercise.
Regular moderate- or high-intensity aerobic exercise induce positive changes in the gut microbiota potentially through the following mechanisms:
Enhancing gut immunity and preserving gut lining integrity
During high-intensity exercise, heat shock occurs, whereby a large proportion of blood flows to the muscles to supply oxygen and skin surface for cooling. Heat shock reduces intestinal blood flow by more than 50% thus reduces the gut’s oxygen supply.
Since the gut lining cells require oxygen for respiration, high-intensity exercise transiently impairs gut lining function, which may briefly result in more direct contact between the gut lining immune system and gut microbes. This has positive health effects, as exercise also stimulates gut immune cells’ production, which produce antimicrobial factors to preserve beneficial gut microbes.
Upon rest, contact between microbes and the gut lining immune system reduces, but those who exercise regularly have less harmful microbes in their blood at rest and produce more heat shock proteins as exercise resumes. Increased heat shock proteins in the gut have been shown to prevent the breakdown of the gut lining, so exercise may stimulate beneficial adaptations in the gut and improve the gut lining’s long-term resilience.
Muscle contraction
Contraction of skeletal muscles is what makes exercise possible, but prolonged muscle contraction produces lactate, a substance that causes muscle soreness. If lactate were diverted from the muscles to the gut, it would facilitate the growth of lactic acid bacteria, a type of beneficial gut microbe.
Strategy #3 - Ensure good mental well-being
Chronic psychological stress also makes losing weight hard, since it is a stimulator of excessive cortisol secretion. Uncontrolled cortisol secretion results in a hyperactive HPA axis-induced hormonal imbalance, overeating and weight gain. Therefore, ensuring good mental well-being of oneself is another remedy to hormonal imbalance and weight gain.
If you are going through hard times and would like to lose weight, the above two strategies - following a MD and exercising regularly - would apply to you.
The MD can help enhance your mental health in many ways:
1) By stimulating the production of SCFAs - SCFAs produced by fermentation of plant-based components in the MD reduce anxiety and depressive-like behaviors, as they attenuate HPA-axis activation following a stressful event, and stimulate the production of relaxing brain chemicals
2) By slowing down glucose absorption - non-digestible carbohydrates (like dietary fiber) is absorbed at a slower rate than fast-digesting carbohydrates (like table sugar), which avoids glucose spikes - a “culprit” to mood swings
3) By encouraging a high consumption of omega-3 FAs, and discouraging a high consumption of animal proteins, saturated fats, processed foods and high-sugar foods can improves brain signaling and act as anti-inflammatory agents, which are lacking as one experiences depressive symptoms
Exercise is another important element for destressing. As you engage in physical activity, your brain secretes endorphins - mood-elevating hormones that have relaxing effects. Additionally, exercise alleviates inflammation through positive changes in the gut microbiota. As colonies of beneficial gut microbiota expand, inflammation is less likely to occur, which provides no stimulus to initiate a cortisol secretion cascade.
The above strategies are not an exhaustive list of solutions to hormonal imbalance and weight gain, but this article, at the very least, adds one more reason to adhere to a MD long-term, exercise regularly and use appropriate stress-coping strategies. Not only may this restore hormonal balance and a normal weight, but may also improve your mental health, which is crucial to body weight maintenance.
(The content is informative only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Please consult a medical professional if you have doubts over the above information.)
References:
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3. Garcia-Mantrana, I., Selma-Royo, M., Alcantara, C., & Collado, M. C. (2018). Shifts on Gut Microbiota Associated to Mediterranean Diet Adherence and Specific Dietary Intakes on General Adult Population. Frontiers in microbiology, 9, 890. https://doi.org/10.3389/fmicb.2018.00890
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5. Mailing, L. J., Allen, J. M., Buford, T. W., Fields, C. J., & Woods, J. A. (2019). Exercise and the Gut Microbiome: A Review of the Evidence, Potential Mechanisms, and Implications for Human Health. Exercise and sport sciences reviews, 47(2), 75–85.
6. Silva Y.P., Bernardi A., & Frozza RL (2020). The Role of Short-Chain Fatty Acids From Gut Microbiota in Gut-Brain Communication. Front. Endocrinol. 11:25. https://10.3389/fendo.2020.00025
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