Hormones And Weight Loss

Hormones are chemical messengers in our body and they control an array of different processes including metabolism and reproduction. 

Sometimes hormonal imbalances can occur in certain circumstances leading to too much or too little of important hormones and in some cases this can lead to weight gain or weight loss. 

On the other hand the actual gain or loss of weight can cause our hormone levels to change which can affect some of our bodily processes. 

Leptin 

Leptin is a hormone that is released from our fat cells, its role is to tell the body that we are full  and to stop eating when we have an adequate store of fuel. Usually when we lose weight, our levels of fat reduce and leptin levels reduce in line with our fat stores. With less fat cells, less leptin is produced meaning our bodies get less of the fullness signal and we naturally become hungrier. 

From an evolutionary perspective this mechanism ensures we don’t lose too much weight however, it can lead to high rates of weight regain often seen after a significant weight loss. 

Sometimes people of a higher weight can become resistant to the hormone leptin, when we have resistance to it, even when it is released in high amounts, the body doesn’t get the signal to say stop eating, they remain hungry even though our stores are full, and this can lead to excess weight gain (1). 

For people with leptin resistance dieting can promote the feeling of hunger further, reducing the success of a diet. Eating foods higher in protein (2) can help to reduce appetite due to the satiating effects of this macronutrient. The use of a high protein, low calorie diet can be useful to lose weight and make long term changes that can help to regulate leptin levels in people who may be leptin resistant and looking to lose a large amount of weight (3). 

Insulin 

A higher body weight is associated with resistance to the hormone insulin which can lead to conditions like type 2 diabetes. Weight loss can improve sensitivity to insulin and improve blood sugar control (4). Therefore weight loss can reduce the risk of developing type 2 diabetes and other longer term health conditions such as cardiovascular disease.  

Reproductive hormones

Women with PCOS or Polycystic Ovary Syndrome can have hormonal imbalances, namely resistance to insulin and higher levels of androgens (male hormones) such as testosterone. Together this can make it harder for some people with PCOS to lose weight (5). Strategies such as moderating carbohydrate intake and increasing protein intake can help to aid weight loss, reduce insulin resistance and balance sex hormone levels in women with PCOS. 

During menopause there is a decline in the hormone oestrogen (6). Oestrogen helps to protect against increased body fat through its effects on appetite, energy expenditure & body composition helping pre menopausal women to maintain a healthy weight and a healthy body composition. Women going through or having gone through the menopause can often find it harder to lose weight and find they store fat around their middle or abdomen rather than on the hips and thighs as they did prior to menopause. These hormonal changes leading to an increase of abdominal fat can increase the risk of cardiometabolic disease and  insulin resistance (7,8).

A diet with reduced calories and a lower glycaemic load can help to aid weight loss. Including more protein in the diet can help to protect against muscle loss and reduce appetite in menopausal women when on a lower calorie diet. Exercise is also important to protect muscle and bone mass at this time of life. 

Being of a higher weight can lead to raised levels of the reproductive hormones oestrogen and androgens which can increase risk for breast cancer. Weight loss has been shown to significantly reduce oestrogen and testosterone levels, which are markers of breast cancer risk (9,10).  

Women with a very high BMI experience more menstrual cycle abnormalities, anovulation, infertility and miscarriage than their lower weight counterparts and this has been related to changes in the levels of certain reproductive hormones. For those carrying extra weight, weight loss can improve menstrual cycle regularity, fertility, reproductive hormone levels promoting chances of conception as well as a positive pregnancy outcome (11). 

The bottom line

Our weight changes more than just our shape and size. Implementing dietary strategies that can help us to achieve and more crucially maintain a healthy weight are important to balance our hormone levels and protect our health. The best way to do this may be different in certain situations and so it is recommended to seek the advice of a healthcare professional to help you on your journey.  

It is important to note that losing too much weight or over-exercising can have a detrimental effect on our hormone levels and on our health (12). For example, having too low a BMI (18.5 or less) can be detrimental for fertility outcomes due to a reduction in the amount of oestrogen produced. 

References 

1. Crosignani PG, Colombo M, Vegetti W, Somigliana E, Gessati A, Ragni G. Overweight and obese anovulatory patients with polycystic ovaries: Parallel improvements in anthropometric indices, ovarian physiology and fertility rate induced by diet. Hum Reprod [Internet]. 2003 Sep 1 [cited 2021 May 27];18(9):1928–32. Available from: https://pubmed.ncbi.nlm.nih.gov/12923151/
2. Weigle DS, Breen PA, Matthys CC, Callahan HS, Meeuws KE, Burden VR, et al. A high-protein diet induces sustained reductions in appetite, ad libitum caloric intake, and body weight despite compensatory changes in diurnal plasma leptin and ghrelin concentrations. Am J Clin Nutr [Internet]. 2005 [cited 2021 Feb 25];82(1):41–8. Available from: https://pubmed.ncbi.nlm.nih.gov/16002798/
3. Berg A. The Influence of a Meal Replacement Formula on Leptin Regulation in Obese Adults. J Nutr Heal Food Sci. 2016 Sep 14;4(4):1–5. 
4. Brown A, Leeds AR. Very low-energy and low-energy formula diets: Effects on weight loss, obesity co-morbidities and type 2 diabetes remission – an update on the evidence for their use in clinical practice [Internet]. Vol. 44, Nutrition Bulletin. Blackwell Publishing Ltd; 2019 [cited 2021 May 27]. p. 7–24. Available from: https://onlinelibrary.wiley.com/doi/full/10.1111/nbu.12372
5. Barber TM, Franks S. Obesity and polycystic ovary syndrome [Internet]. Clinical Endocrinology. Blackwell Publishing Ltd; 2021 [cited 2021 May 27]. Available from: https://pubmed.ncbi.nlm.nih.gov/33460482/
6. Karvonen-Gutierrez C, Kim C. Association of Mid-Life Changes in Body Size, Body Composition and Obesity Status with the Menopausal Transition. Healthcare [Internet]. 2016 Jul 13 [cited 2020 Nov 5];4(3):42. Available from: https://pubmed.ncbi.nlm.nih.gov/27417630/
7. Chopra S, Sharma K, Ranjan P, Malhotra A, Vikram N, Kumari A. Weight management module for perimenopausal women: A practical guide for gynecologists [Internet]. Vol. 10, Journal of Mid-Life Health. Wolters Kluwer Medknow Publications; 2019 [cited 2020 Oct 30]. p. 165–72. Available from: /pmc/articles/PMC6947726/?report=abstract
8. Mason C, De Dieu Tapsoba J, Duggan C, Wang CY, Alfano CM, McTiernan A. Eating behaviors and weight loss outcomes in a 12-month randomized trial of diet and/or exercise intervention in postmenopausal women. Int J Behav Nutr Phys Act [Internet]. 2019 Nov 27 [cited 2020 Oct 23];16(1). Available from: https://pubmed.ncbi.nlm.nih.gov/31775800/
9. Campbell KL, Foster-Schubert KE, Alfano CM, Wang CC, Wang CY, Duggan CR, et al. Reduced-calorie dietary weight loss, exercise, and sex hormones in postmenopausal women: Randomized controlled trial. J Clin Oncol [Internet]. 2012 Jul 1 [cited 2021 May 27];30(19):2314–26. Available from: https://pubmed.ncbi.nlm.nih.gov/22614972/
10. de Roon M, May AM, McTiernan A, Scholten RJPM, Peeters PHM, Friedenreich CM, et al. Effect of exercise and/or reduced calorie dietary interventions on breast cancer-related endogenous sex hormones in healthy postmenopausal women [Internet]. Vol. 20, Breast Cancer Research. BioMed Central Ltd.; 2018 [cited 2021 May 27]. p. 1–16. Available from: https://doi.org/10.1186/s13058-018-1009-8
11. Rochester D, Jain A, Polotsky AJ, Polotsky H, Gibbs K, Isaac B, et al. Partial recovery of luteal function after bariatric surgery in obese women. Fertil Steril [Internet]. 2009 Oct [cited 2021 May 27];92(4):1410–5. Available from: https://pubmed.ncbi.nlm.nih.gov/18829008/
12. Morrison AE, Fleming S, Levy MJ. A review of the pathophysiology of functional hypothalamic amenorrhoea in women subject to psychological stress, disordered eating, excessive exercise or a combination of these factors [Internet]. Clinical Endocrinology. Blackwell Publishing Ltd; 2021 [cited 2021 Jun 1]. Available from: https://pubmed.ncbi.nlm.nih.gov/33345352/