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Low Leptin Levels Can Be Concerning: Our Functional Medicine Toronto Clinic Sheds Light


In a previous post from our functional medicine Toronto clinic, we explained that excessive amounts of leptin could contribute to obesity and hinder active thyroid function. So, what happens when you have low amounts of this hormone? Well, it could impact optimal health, too.

Understanding this hormone’s role

Sometimes called the “starvation hormone”, leptin is formed by your fat cells and tells your hypothalamus when and how much to eat for energy expenditure. Quite simply, the amount increases when your fat cells increase. “When you eat, your body fat goes up, leading your leptin levels to go up. Thus, you eat less and burn more. Conversely, when you don’t eat, your body fat goes down, leading your leptin levels to drop. At that point, you eat more and burn less,” explains Healthline.

Bottom line: leptin stimulates feelings of fullness and tells your brain, “Stop, you’ve eaten enough!” Now leptin resistance occurs when the body carries excessive amounts of the hormone and your body no longer responds to it. When this happens, you don’t feel satiated after eating; so you might continue eating, despite having enough fat stores.

When you lack this hormone or have low amounts, your body acts like it doesn’t have enough fat; because leptin is not present or you only have low amounts, this can generate overeating and obesity because leptin isn’t telling the body to start or stop eating.

But low leptin levels can also transition your body into “starvation mode.” When this happens, your body will lessen its energy levels and you use less calories. It’s no wonder low levels of this “satiety” hormone are affiliated with poor cognition, a mental health issue like depression, anorexia or repeated infections.

Ghrelin vs. Leptin: What’s the Difference?
These are both known as “hunger” hormones. This is because ghrelin’s role is to simply tell the brain that you’re hungry. However, leptin is an appetite suppressor that encourages the body to resume or stop eating for the purpose of balancing energy levels.

How low levels could hinder optimal function

Having a shortage of this hormone can impact wellness in different ways. Here are a few examples:

  • Immune function: According to a Natures Review Rheumatology piece, leptin might assist with strengthening the immunity: “Leptin participates in innate immunity by inhibiting natural killer cells and by inducing proliferation and activation of monocytes.”
  • Depression: In one study, these hormone levels were measured low in depressed women of different weights.  “These data support animal studies implicating leptin as a neurotrophic hormone with antidepressant and anxiolytic effects,” confirms a Clinical Endocrinology article.
  • Memory issues: Subdued leptin levels might impede cognition. But according to Nature Reviews Neuroscience, “Chemical messages derived from adipose tissue through leptin can activate specific receptors in the hippocampus and the hypothalamus, and influence learning and memory.”
  • Fertility and bone health: HA (hypothalamic amenorrhea) occurs when the menstrual periods of females with low body fat are suspended; this can potentially cause infertility and osteoporosis. In one study, it was shown that leptin might help reestablish fertility and bone health in women with HA. “… leptin is the missing link in women with significantly diminished body fat, and that this, in turn, results in numerous hormonal abnormalities,” Christos Mantzoros, MD, Dsc, Director of the Human Nutrition Unit at BIDMC and Professor of Medicine at Harvard Medical School, told ScienceDaily.

The following health concerns are connected to low leptin levels:

  • Osteoporosis
  • Excessive amount or low amount of body fat
  • Slow metabolism
  • Frequently feeling hungry
  • Absence of menstrual periods

The functional medicine approach to hormonal shortcomings

If you’re concerned about leptin levels, a functional medicine practitioner could offer a personalized approach to addressing this concern, as well as helping you reach your health goals. And because individual symptoms can overlap with underlying conditions, seeking help from healthcare providers could bring attention to other aspects of health.

At the Toronto Functional Medicine Centre, our integrative medicine consultants may recommend functional medicine testing at your initial visit. This is necessary for scrutinizing hormone levels and possible nutritional deficiencies. From there, they customize your treatments with different tools, like nutraceuticals, dietary changes, and more. Sleep modifications might be recommended, too, because short sleep durations have been linked to low levels of leptin.

Are you interested in becoming a new patient at our clinic? Our clinic can offer assistance for various chronic conditions (i.e. chronic pain, chronic fatigue) autoimmune illness, digestive issues, nutritional deficiencies, stress management, blood pressure issues, infertility, brain fog, sexual health, and more.

About our healthcare providers and clinic services

At the Toronto Functional Medicine Centre, our healthcare providers are dedicated to educating and empowering patients towards optimal health. They adhere to functional medicine wisdom, which views each patient as an exceptional entity; thus, we treat each patient according to their own individual symptoms and health concerns. Lifestyle modifications, environmental factors, past health issues and genes are considered when tackling the root cause of your condition.

Integrative medicine is also a focus at our private practice. Our patients have access to a wide variety of clinical therapies, such as Western medicine, herbal medicine, Traditional Chinese Medicine, bio-identical hormone replacement therapy, IV therapy, and other approaches to health. Your comfort is critical to us, which is why we offer both in-person and virtual consultations.

Do you think your hormonal health needs tweaking? Our integrative care could help you uncover new strategies to upgrade your wellness. Contact us by calling (416) 968-6961 or use this form to send us a message.

Disclaimer: The information in this article is designed for educational purposes only and is not intended to be a substitute for informed medical advice or care. This information should not be used to diagnose or treat any health problems or illnesses without consulting a doctor. Consult with a health care practitioner before relying on any information in this article or on this website.



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Beth Israel Deaconess Medical Center. “Leptin restores fertility, may improve bone health in lean women; Treatment could help athletes, women with eating disorders.” ScienceDaily. ScienceDaily, 6 April 2011. <>.

Blüher S, Shah S, Mantzoros CS. Leptin deficiency: clinical implications and opportunities for therapeutic interventions. J Investig Med. 2009 Oct;57(7):784-8. doi: 10.2310/JIM.0b013e3181b9163d. PMID: 19730134; PMCID: PMC5501320.

Friedman JM. Leptin and the regulation of body weigh. Keio J Med. 2011;60(1):1-9. doi: 10.2302/kjm.60.1. PMID: 21460597.

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Lawson EA, Miller KK, Blum JI, Meenaghan E, Misra M, Eddy KT, Herzog DB, Klibanski A. Leptin levels are associated with decreased depressive symptoms in women across the weight spectrum, independent of body fat. Clin Endocrinol (Oxf). 2012 Apr;76(4):520-5. doi: 10.1111/j.1365-2265.2011.04182.x. PMID: 21781144; PMCID: PMC3296868.

Leptin and Leptin Resistance: Everything You Need to Know” from Healthline, By Kris Gunnars, BSc — Updated on December 4, 2018, viewed on October 9, 2022. 

Patricia Fernández-Riejos, Souad Najib, Jose Santos-Alvarez, Consuelo Martín-Romero, Antonio Pérez-Pérez, Carmen González-Yanes, Víctor Sánchez-Margalet, “Role of Leptin in the Activation of Immune Cells”, Mediators of Inflammation, vol. 2010, Article ID 568343, 8 pages, 2010.

Taheri S, Lin L, Austin D, Young T, Mignot E. Short sleep duration is associated with reduced leptin, elevated ghrelin, and increased body mass index. PLoS Med. 2004 Dec;1(3):e62. doi: 10.1371/journal.pmed.0010062. Epub 2004 Dec 7. PMID: 15602591; PMCID: PMC535701.

Your ‘Hunger Hormones’: How they affect your appetite and your weight”, on WebMD, written by Elaine Magee, MPH, RD, Reviewed by Brunilda Nazario, MD, viewed on October 10, 2022. 


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