As a gut-health dietitian, I often emphasize the importance of understanding how our diet choices, including the types of foods and when we eat them, influence our overall well-being. Today, we will explore the intricate world of macronutrients and specific dietary approaches—like the low-carb/Keto diet and fasting—and their impacts on thyroid and gut health.

Macronutrients and Their Effect on Thyroid Health

To start, let’s break down what macronutrients are. Essentially, they’re the nutrients our body needs in large amounts: carbohydrates, proteins, and fats. Each plays a unique role in our health.

Carbohydrates: Carbs, often vilified in today’s diet culture, are SO important, as they’re our body’s primary energy source. The thyroid gland requires glucose, a form of carbohydrate, to trigger the release of a hormone called thyrotropin-releasing hormone. This hormone tells our pituitary gland to produce thyroid-stimulating hormone (TSH), which then prompts the thyroid gland to release its hormones. These hormones govern everything from metabolism to mood. Without adequate carbohydrate intake, our body can potentially struggle to regulate these essential functions. In other words, carbs help our thyroid work correctly.

Proteins: Essential for tissue repair and production of enzymes and hormones. The thyroid gland utilizes specific amino acids, the building blocks of protein, to produce its hormones. 

Fats: Fats are crucial for hormone production, including thyroid hormones. Research has indicated that omega-3 fats can reduce inflammation that might impact the thyroid. This anti-inflammatory effect of omega-3s can be especially helpful for individuals with autoimmune thyroid issues like Hashimoto’s. In such conditions, the immune response targets the thyroid, leading to inflammation. This can trigger the release of thyroid antibodies, potentially causing hypothyroidism (when the thyroid gland doesn’t produce enough thyroid hormone). Omega-3s help maintain the health of cell membranes, ensuring they remain undamaged and facilitating effective cell communication.

Low Carb/Keto Diet and Its Effects on Thyroid and Gut Health

The ketogenic or “keto” diet is a high-fat, low-carb diet that has gained immense popularity for its potential weight loss benefits. But what does it mean for our thyroid and gut?

Thyroid: While the keto diet can help some people, there are concerns about how it affects thyroid health. By drastically reducing carb intake, there may be less glucose available for thyrotropin-releasing hormone production, potentially impacting thyroid function. Some individuals on long-term, very low-carb diets have reported elevated TSH levels, a marker that the thyroid might not be functioning optimally. 

Additionally, the majority of the thyroid hormone (T4) produced by the thyroid gland isn’t immediately usable by the body. It needs to be activated by organs like the liver through a process known as deiodination. The end result of this process is the active thyroid hormone, T3.

Studies indicate that:

• Carbohydrates play an important role in deiodination and influence T3 levels in the body.
• And the amount of carbohydrates in your diet directly impacts how much of T4 gets converted to T3, the functional form of thyroid hormone. 

Gut: Our gut loves fiber—a carbohydrate. On a strict keto diet, there might be a reduction in fiber intake, which can affect gut bacteria. Beneficial bacteria feed on fiber, producing short-chain fatty acids that maintain a healthy gut lining. Without enough fiber, we might starve these friendly bacteria, potentially affecting our overall gut health. Some research has shown that a low-carb diet not only decreases overall bacterial levels but also diminishes bacterial variety. Furthermore, research has identified shifts in the types of probiotics present, with low-carb diets leading to a decrease in beneficial, inflammation-fighting species and an increase in less favorable probiotic types.

Fasting and Its Effects on Thyroid and Gut Health

Intermittent fasting, where individuals cycle between eating and fasting periods, has been highlighted for its potential health benefits, from weight loss to improved brain function. But how does it impact our thyroid and gut?

Thyroid: Research indicates that intermittent fasting can significantly impact thyroid function, as it can cause T3 levels to drop by more than half in the blood during fasting periods. This could be concerning for individuals with hypothyroidism, given that their thyroid already lacks this particular hormone. The good news is that these impacts are short-lived. After eating your subsequent meal, the thyroid hormone levels should return to what they were before the fasting period. In essence, while short-term fasting might not drastically impact thyroid health for most people, longer fasting periods could. Keep in mind that the stricter your diet, the higher the chances of triggering inflammation. Such inflammation can amplify autoimmune responses or disrupt your thyroid’s functioning. Therefore, it’s important to follow a dietary approach that you can sustain over time (which is exactly what I help my clients achieve! Learn more here.)

Gut: Fasting gives our digestive system a break, potentially promoting repair and reducing inflammation. Intermittent fasting may have some benefits on our gut microbiota, however, most research is based on animals or limited human studies, often during Ramadan. 

Additionally, there may be some benefit for those who have an imbalance in their gut microbiota (aka dysbiosis). Other potential benefits are that possible changes can lead to genetic shifts relating to carbohydrate metabolism, which may help to improve blood glucose and body mass index. These benefits tend to occur with longer time-restricted feeding windows of 16 hours or more.

Bottom Line

Diet choices, from the types of foods we consume to when we eat them, play a crucial role in our thyroid and gut health. It’s essential to remember that every individual is unique. What works wonders for one person might not for another. As a gut-health dietitian, my advice is always to listen to your body, stay informed, and consult with health professionals before making significant dietary changes. Your body, especially your thyroid and gut, will thank you for it!

Welcome to the world of nutrition, where each nutrient plays a unique and essential role in our health and wellbeing. Today, we’re diving deep into the fascinating world of protein! This isn’t just about muscle gains or fitness fads; it’s about uncovering the deeper roles that protein plays in our bodies. As a Registered Dietitian, I get to wear my nutrition detective hat every day, and I’m passionate about sharing this knowledge with you. Together, we’ll explore how this mighty macronutrient is not just about building muscles, but is also a star player in supporting our overall health and wellbeing. So, grab a cup of your favorite tea, make yourself comfy, and let’s dive into the fantastic world of protein!

What is protein?

Protein is one of the three essential macronutrients, alongside carbohydrates and fats. It is composed of small units called amino acids, which are often referred to as the building blocks of life. Our body uses 20 different types of amino acids to construct various proteins, which perform various functions, from creating structural components of cells to acting as enzymes, antibodies, and messengers.

What are the benefits of protein?

• Reproductive Health and Hormone Balance: Hormones are chemical messengers that play a vital role in our body, including our reproductive health. A balanced intake of protein can help in the formation and regulation of hormones, including those related to fertility (such as peptide hormones).[1,2] This is because proteins help to stabilize our blood sugar levels by slowing the absorption of glucose from the carbohydrates we eat, which in turn helps to regulate insulin levels—a hormone produced by the pancreas. This balancing act is crucial as consistently high sugar levels can lead to insulin resistance and other hormonal imbalances.[1] Additionally, eating protein-rich foods can make us feel fuller for longer, reducing the chances of overeating and weight gain, which is vital since excess body fat can further disrupt our hormone balance.[1]

• Glucose Tolerance: Protein can play a role in improving glucose tolerance, which is crucial for managing and preventing diabetes. Consuming protein with a meal can help slow the absorption of carbohydrates and thus reduce the post-meal rise in blood sugar. A randomized controlled trial compared the effects of diets with varying amounts and sources of protein on insulin sensitivity in individuals with obesity and insulin resistance. The results demonstrated that after one month, high-protein, low-calorie diets significantly improved insulin sensitivity by 60-90% in these individuals, regardless of weight loss and whether the protein source was animal or vegetable.[3] In another study, 20 insulin-resistant obese women were assigned to either a Mediterranean diet or a high-protein diet, both containing the same number of calories, to compare how these diets affected their metabolic health. The results showed that the high-protein diet was more effective than the Mediterranean diet in reducing insulin resistance and improving blood sugar stability.[4] 

• Maintaining a Healthy Weight: Incorporating protein-rich foods into your meals can be a game-changer for weight management. Consuming enough protein can help you feel fuller for longer, thereby reducing unnecessary snacking and overeating.[5] For example, a study of 156 obese Chinese adolescents were randomly assigned to eat either a high-protein egg breakfast or a steamed bread breakfast.[6] The results showed that the group eating the egg breakfast experienced increased feelings of fullness, ate less food at lunchtime, and had reduced body weight after three months.[6] This group also had higher levels of hormones that promote feelings of fullness (PYY and GLP-1), suggesting that the high-protein breakfast helped with weight loss by making these adolescents feel fuller and eat less later in the day.[6]
• Sarcopenia and Healthy Muscle Mass: Sarcopenia, or muscle loss, is a major risk factor for health problems in older adults, and studies have shown that not getting enough energy and protein is linked to reduced muscle mass in this group.[7] Having adequate muscle mass can help prevent metabolic syndrome. In a study involving 90 healthy Japanese women aged 65 years and older, researchers looked at how body composition, specifically muscle mass and visceral fat (the fat around internal organs), is related to metabolic syndrome (MetS) – a group of conditions that increase the risk of heart disease and other health problems.[8] The results showed that having more visceral fat was linked to a higher risk of MetS, while having more muscle mass was linked to a lower risk of MetS, even after accounting for the amount of visceral fat a person had.[8] This suggests that keeping muscle mass up in older age might help protect against heart disease and other health problems related to MetS.[8]

How much protein do I need?

Protein requirements can vary based on several factors, including age, sex, physical activity level, and overall health. Here are the general daily protein recommendations for adult males and females, but it’s important to consult with a healthcare professional for personalized advice. For adult males, the Recommended Dietary Allowance (RDA) for protein is 56 grams per day and for adult women, it’s 46 grams per day. 

Foods high in protein 

Here are some of the top sources of protein per 3.5 ounces/100 grams serving:[9] 

• Lean chicken breast: 32 grams
• Lean pork chops: 31 grams 
• Tuna: 29.9 grams 
• Skirt steak beef: 28.7 grams 
• Firm tofu: 17.3 grams 
• Lentils: 9 grams 
• Low-fat yogurt: 5.7 grams 
• Eggs: 12.6 grams 

Include a variety of these in your diet to ensure you’re not only meeting your protein needs but also getting all the essential amino acids your body requires.

Bottom Line:

Protein is far more than a nutrient for those looking to build muscle; it is a critical part of overall health. From playing a role in hormone balance to assisting in weight management, glucose tolerance, and maintaining vibrant muscles as we age, protein is indeed a powerhouse nutrient.

Remember, everyone’s protein needs are different and it’s essential to find what works best for your unique body and lifestyle. Need extra guidance? Book a free call with me here! I’m here to answer your questions and help you navigate your path to optimal health through nourishing food choices.

References:

1. Peeru, S. Protein rich foods are important in hormonal balance. Linkedin.com.
2. Lang, A., BSc, & MBA. (2021, November 3). Everything you should know about hormonal imbalance.
3. González-Salazar, L. E., Pichardo-Ontiveros, E., Palacios-González, B., Vigil-Martínez, A., Granados-Portillo, O., Guizar-Heredia, R., Flores-López, A., Medina-Vera, I., Heredia-G-Cantón, P. K., Hernández-Gómez, K. G., Castelán-Licona, G., Arteaga-Sánchez, L., Serralde-Zúñiga, A. E., Ávila-Nava, A., Noriega-López, L. G., Reyes-García, J. G., Zerrweck, C., Torres, N., Tovar, A. R., & Guevara-Cruz, M. (2021). Effect of the intake of dietary protein on insulin resistance in subjects with obesity: a randomized controlled clinical trial. European Journal of Nutrition, 60(5), 2435–2447. 
4. Tettamanzi, F., Bagnardi, V., Louca, P., Nogal, A., Monti, G. S., Mambrini, S. P., Lucchetti, E., Maestrini, S., Mazza, S., Rodriguez-Mateos, A., Scacchi, M., Valdes, A. M., Invitti, C., & Menni, C. (2021). A high protein diet is more effective in improving insulin resistance and glycemic variability compared to a Mediterranean diet—A cross-over controlled inpatient dietary study. Nutrients, 13(12), 4380.
5. Pugle, M. (2018, June 22). How 30 grams of protein at breakfast can help you lose weight. Healthline Media.
6. Wang, S., Yang, L., Lu, J., & Mu, Y. (2015). High-protein breakfast promotes weight loss by suppressing subsequent food intake and regulating appetite hormones in obese Chinese adolescents. Hormone Research in Paediatrics, 83(1), 19–25.
7. Landi, F., Calvani, R., Tosato, M., Martone, A., Ortolani, E., Savera, G., D’Angelo, E., Sisto, A., & Marzetti, E. (2016). Protein intake and muscle health in old age: From biological plausibility to clinical evidence. Nutrients, 8(5), 295. 
8. Nomura, K., Eto, M., Ogawa, S., Kojima, T., Iijima, K., Nakamura, T., Araki, A., Ouchi, Y., & Akishita, M. (2020). Association between low muscle mass and metabolic syndrome in elderly Japanese women. PloS One, 15(12), e0243242.
9. Whitbread, D. (2009, March 9). Top 10 foods highest in protein. Myfooddata; My Food Data.