Brooke OkeHunger Hormones.
We have picked the brains of Elizabeth from Elizabeth Anne Nutrition to understand why and how your hunger hormones can help you to improve your relationship with food.
Let's dive in!
Hunger hormones are produced as a mechanism for the body to maintain homeostasis and balance energy output with energy consumption.
We alternate between periods of hunger to increase energy consumption when stores are low and satiation to reduce intake when energy stores are adequate i.e. we have eaten enough food.
In our fast-paced lives we often try to override hunger signals in favour of pushing through an extra hour of work, having a cup of coffee, or going to the gym. Restrictive diets effect our hunger hormones as much as the consumption of high energy fast foods do.
The body’s main concern is gathering sufficient energy from the foods that we eat during the day to support the functioning of vital bodily organs.
Hunger hormones are affected by numerous factors including:
Nutritional deficiencies – zinc, protein, fibre, carbohydrates
Nutritional excesses – high GI carbohydrates, refined foods
Eating habits i.e. eating on the go or too quickly
Obesity or overweight body status
Thyroid hormone disorders
Periods of increased stress
Low levels or lack of physical activity
Disordered eating behaviours
Insulin resistance
Depression
Anxiety
When hunger hormones are out of balance you may experience:
Increased and persistent hunger even after eating
Feelings of increased fullness after eating
Low energy
Dizziness
Agitation when hungry a.k.a. hangry
Lack of appetite
Here’s a rundown of the main hormones that regulate appetite:
Leptin
Leptin is a protein that acts as a hormone to promote satiety
Signals from adipose tissue (fat tissue/cells) that energy stores are sufficient to create a negative energy balance
Suppresses appetite and increases energy expenditure following a satiating meal
Leptin is also secreted by stomach cells in response to food
Plays a role in short-term and long-term satiety regulation
With obese and overweight body weight status leptin levels increase to overcome insensitivity and resistance to leptin
Leptin resistance develops overtime when leptin signals are continually overruled despite consumption of adequate energy intake
Adiponectin
Is produced by adipose tissue
Higher levels of adiponectin are found in correlation with lower levels of body fat
Reduces inflammation, promotes insulin sensitivity
Protective against type 2 diabetes, CVD, insulin resistance
Ghrelin
Is secreted by stomach cells
Promotes positive energy balance – stimulates appetite and encourages consumption of fuel for energy storage
Triggers the urge to eat
Increased ghrelin levels found in blood before meals
Ghrelin’s purpose is to maintain stable body weight
Higher ghrelin levels are generally found in lean people
Lower ghrelin levels are generally found in overweight people
Peptide YY (PYY) – promotes satiety
Is secreted by GI cells after a meal
Signals satiety and decreases food intake
Cholecystokinin
Is released from the intestinal wall in response to fat or protein in the small intestine
Slows GI tract motility to allow all reactions needed for fat and protein digestion to complete
Lower levels found with obese and overweight body weight status
Other important points about hunger hormones –
the role of fibre, the Vagus nerve and neurotransmitters.
Short chain fatty acids (SCFA’s) can act on free fatty acid receptor 2 to stimulate the release of the hormone peptide YY (PYY), thus playing a direct and significant role in inducing satiety.
Dietary fibre is the major source of SCFA’s therefore increasing your intake of fruits, vegetables and whole-grains is beneficial for the regulation of hunger hormones. SCFA’s are known for their modulatory effects on immunity, gastrointestinal epithelial cell integrity (gut cell health), lipid metabolism, glucose homeostasis, and appetite.
The vagus nerve (connects the gut and the brain) is involved in appetite regulation following a meal due to distention of the stomach following food consumption, many hunger hormones are also produced by cells in the gut which the vagus nerve innervates. Therefore, following food consumption signals are sent to the brain to say that either enough food has been consumed or that more food is needed.
The neurotransmitters Dopamine and Serotonin may also be involved in appetite regulation in that there are times where reward pathways related to pleasure and enjoyment of food override the usual mechanisms of control.
How to support the regulation of hunger hormones:
Mindful eating
When combined with a balanced diet mindful eating is the most effective way of supporting the balance between hunger stimulating and hunger suppressing hormones. The practice of slowing down and paying attention to the food that we are eating; allows our brain to register the signals produced by receptors in the gut telling the brain that we have eaten enough and can stop eating. Conversely, when we pay attention to hunger signals that tell us when we are hungry rather than ignoring them and replacing with work, exercise, or coffee, we become more in tune with our hunger signals. Through practice we begin to trust ourselves, that when we feel hungry, we will provide our body with the energy that it needs.
Eat Balanced meals
Providing your body with adequate energy from macronutrients (carbohydrates, protein, fats, fibre) and micronutrients (vitamins and minerals) supports appetite regulation. When in an energy deficit i.e. as a result of a restrictive diet for weight loss, our body looks to quick sources of energy often in the form of refined sugar and processed foods. By eating balanced meals, you will reduce your risk of nutrient deficiencies and provide your body with adequate energy and nutrients to support the function of vital organs and cellular energy production.
Support gut health
Increase your intake of prebiotic foods, these foods increase the production of short chain fatty acids (SCFA) in the gut which support gut/brain communication pathways. Reduce your intake of highly processed foods that are high in energy and low in nutritional value. These cause inflammation and over time result in damaging and depleting beneficial bacteria in the gut.
Exercise
The mechanism in which exercise helps to regulate appetite is not thoroughly understood and most research has been conducted on males; however, exercise is likely to:
Suppress ghrelin concentrations during running and resistance exercise and for up to one hour following exercise
Increase PYY concentrations during aerobic exercise and for up to 5 hours after exercise
This means that you will generally feel less hungry during and after exercise.
Studies have shown that there is a difference in the response of energy regulating hormones in males and females in response to exercise. A small study showed that women have a more robust hormonal response which leads to the stimulation of appetite as a mechanism to increase energy intake compared to men following exercise. Unfortunately, this is thought to be why exercise training for weight loss is more effective for men than for women.
This isn’t the end of the world ladies; it just means that we are more susceptible to appetite changes when we increase exercise. A well-planned diet high in fibre, complex carbohydrates, protein and healthy fats will support you to fuel exercise and regulate your appetite so that you’re not feeling hungry 24/7.
A note on weight loss
Weight loss should take on a holistic approach, by addressing underlying health issues with the support of a health care practitioner in conjunction with sustainable diet and lifestyle changes you will feel supported to lose weight and maintain weight loss in the long run. Diets for weight loss should promote the release of satiating hormones (leptin, PYY and cholecystokinin) and reduce ghrelin which stimulates appetite. Balanced diets containing adequate amounts of macronutrients (protein, fat, carbohydrates) and along with a high fibre intake have been shown to have this effect on hunger hormones.
When prioritising the recommendations above, I would always advise on starting with your diet and mindfulness-based techniques, don’t overcomplicate things! As always, a good place to start when seeking to manage any hormonal imbalances is talking to your health practitioner, they will be able to provide guidance based on your individual needs.
About Elizabeth.
Elizabeth is a registered Clinical Nutritionist. She is passionate about making health simple and sustainable for all. She enjoys collaborating with clients to gain a holistic understanding of their individual health concerns and desired health outcomes.
You can find Elizabeth at Goodkind Wellness Studio on Thursdays & Saturdays and follow her on Instagram @elizabethann_nutritionist.
Reference List
Cork, S. C. (2018). The role of the vagus nerve in appetite control: implications for the pathogenesis of obesity. Journal of Neuroendocrinology. doi:10.1111/jne.12643
Hagobian, T. A., Sharoff, C. G., Stephens, B. R., Wade, G. N., Silva, J. E., Chipkin, S. R., & Braun, B. (2009). Effects of exercise on energy-regulating hormones and appetite in men and women. American journal of physiology. Regulatory, integrative and comparative physiology, 296(2), R233–R242. https://doi.org/10.1152/ajpregu.90671.2008
Stensel, D. (2011). Exercise, Appetite and Appetite-Regulating Hormones: Implications for Food Intake and Weight Control. Annals of Nutrition & Metabolism. Ann Nutr Metab 2010;57(suppl 2):36–42 DOI: 10.1159/000322702
Witney, E., Rady Rolfes, S., Crowe, T., Smith, D. C., Walsh, A. (2017). Understanding Nutrition: Australian and New Zealand Edition: 3rd Edition.