Kore Kast
Kore Kast is a Podcast dedicated to integrating health and wellness with an emphasis on Pilates and Functional Fitness. This weekly Podcast is hosted by Kris Harris, a Certified Pilates Instructor and Personal Trainer. Please subscribe and follow our journey...
Kore Kast
Hungry for the Truth? What Intermittent Fasting Is Really All About
We explore intermittent fasting beyond the hype, examining this popular eating pattern that focuses on when you eat rather than what you eat. Historical context, scientific mechanisms, and evidence-based benefits reveal why this ancient practice is gaining modern attention.
• Different intermittent fasting methods including 16:8, 5:2, eat-stop-eat, and alternate day fasting
• How the body shifts from using glucose to burning fat during fasting periods
• The process of autophagy - your body's cellular cleaning program that ramps up during fasting
• Evidence-based benefits for weight management and metabolic health
• Common myths debunked including concerns about muscle loss and metabolism damage
• Who should consider intermittent fasting and who should absolutely avoid it
• Practical implementation tips from starting gradually to managing hunger
• Personal experiences and varied results from different practitioners
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Welcome back to the Kore Kast. I'm your host, Kris Harris, and I'm thrilled to kick off season four of our journey together through the vibrant world of health and wellness. Whether you're a fitness fanatic, a Pilates enthusiast or someone just beginning to explore your wellness journey, you're in the right place. In this season, we're going to dive deep into a wide array of topics that matter, everything from the latest in Pilates techniques and fitness trends to essential mental health insights and holistic wellness practices. With nearly two decades of experience as a certified personal trainer, pilates instructor and health coach, I'm here to share expert tips, inspiring stories and practical advice to help you live your healthiest, happiest life. It's time to unlock your true potential. Welcome to Season 4. Hey there, and welcome to another episode of Kore Kast. This is Kris, and I'm thrilled you're joining me today. Have you noticed how everyone, from your fitness-obsessed colleague to your favorite celebrity, seems to be talking about intermittent fasting? It's become one of the most buzzed-about health trends in recent years, with promises ranging from rapid weight loss to extended longevity and improved mental clarity. But what's the real story behind this popular eating pattern? Is intermittent fasting just another fad diet, or is there legitimate science backing its benefits? Today we're cutting through the hype to explore what intermittent fasting actually is, the science behind it and whether it might be right for you. We'll separate fact from fiction and give you practical insights you can actually use. So stick around. Your hungry mind is about to be satisfied with some tasty truth.
Kris Harris:Intermittent fasting isn't actually a diet in the traditional sense. It's more about when you eat rather than what you eat. At its core, intermittent fasting is an eating pattern that cycles between periods of eating and fasting. Instead of restricting certain foods, you're restricting the time window in which you consume your calories. Think of it this way Humans have been fasting inadvertently throughout our evolutionary history. Our hunter-gatherer ancestors didn't always have constant access to food, and our bodies developed mechanisms to function without continuous caloric intake. Intermittent fasting essentially taps into this natural biological process.
Kris Harris:There are several popular methods of intermittent fasting, each with different approaches to timing. The most common is probably the 16.8 method. This involves fasting for 16 hours and restricting your daily eating to an 8-hour window. For many people, this simply means skipping breakfast, eating their first meal around noon and finishing their last meal by 8 pm. Another popular approach is the 5.2 method. With this pattern, you eat normally five days of the week and drastically reduce your calorie intake about 500-600 calories on the other two non-consecutive days. These two days are essentially modified fasting days. Then there's the eat-stop-eat method, where you incorporate one or two 24-hour fasts per week. This means going from dinner one day to dinner the next day without consuming calories.
Kris Harris:Though water, black coffee and other non-caloric beverages are typically allowed during all fasting periods, some people practice alternate day fasting, alternating between days of normal eating and days of fasting or significant calorie reduction. There's also the warrior diet, which involves eating small amounts of raw fruits and vegetables during the day and one large meal at night. What all these methods have in common is creating a metabolic switch periods where your body depletes its readily available sugar stores and begins using fat as its primary energy source. This metabolic shift is what many researchers believe drives many of the potential benefits associated with intermittent fasting. It's important to understand that during fasting periods you're still allowed to drink water, black coffee, tea and other non-caloric beverages. Staying hydrated is essential during fasting. Some approaches also allow very small amounts of food during fasting periods, but the strictest forms involve consuming zero calories outside your eating window.
Kris Harris:When we look at fasting through a historical lens, it's fascinating to realize this isn't some new-age health trend. Fasting is perhaps one of the oldest healing traditions in human history, predating modern medicine by thousands of years. Our ancestors didn't have 24-hour grocery stores or refrigerators stocked with food. They experienced natural periods of feast and famine based on hunting success, seasonal food availability and environmental conditions. From an evolutionary standpoint, our bodies developed remarkable adaptations to handle these inconsistent food supplies. We're actually designed to function, and sometimes even thrive, during periods without food. Our metabolic flexibility allows us to switch from using glucose as fuel to burning stored fat through ketosis when food isn't available. This wasn't a bug in human design. It was a critical survival feature.
Kris Harris:Fasting also appears consistently throughout religious and spiritual traditions across virtually every culture. In Christianity we see fasting periods like Lent. In Islam there's Ramadan with its dawn-to-sunset fasting. Judaism has Yom Kippur. Hinduism and Buddhism both incorporate various fasting practices, and many indigenous traditions worldwide include ceremonial fasting. These traditions recognize something fundamental about temporarily abstaining from food it seemed to bring clarity, discipline and sometimes even healing. Ancient medical traditions like Ayurveda and traditional Chinese medicine also prescribed fasting for healing and longevity. Hippocrates, often called the father of medicine, reportedly said to eat when you are sick is to feed your sickness. Historical healing practices often began with a fasting period before any other interventions. Our bodies contain numerous mechanisms that activate during fasting, processes that reduce inflammation, promote cellular repair and improve metabolic efficiency. These aren't random biological accidents, but purposeful adaptations that helped our ancestors survive food scarcity while maintaining optimal function. In many ways, the constant access to food we enjoy today is the historical anomaly, not the periods of fasting that our bodies seem programmed to handle.
Kris Harris:Let's dive into what actually happens inside your body when you're fasting, because the science here is absolutely fascinating. When you stop eating for an extended period, your body undergoes a remarkable series of metabolic shifts that trigger various health-promoting processes. First, let's talk about what happens in the hours after your last meal. Normally, your body relies on glucose from food as its primary energy source. After eating, your pancreas releases insulin to help cells absorb this glucose from your bloodstream. But when you fast for about 8-12 hours, your glucose stores get depleted and insulin levels drop significantly. This is where things get interesting. Your body, brilliantly designed to never leave you without energy, switches to Plan B. It begins breaking down stored fat into compounds called ketones. This metabolic state is known as ketosis. Unlike glucose, which can't cross the blood-brain barrier efficiently, ketones provide an excellent alternative fuel for your brain. Many people report mental clarity during fasting, and this shift to ketone metabolism may be partly responsible. Around the 16 to 24-hour mark of fasting, and this shift to ketone metabolism may be partly responsible.
Kris Harris:Around the 16 to 24 hour mark of fasting, a process called autophagy ramps up significantly. Think of autophagy as your body's internal recycling program. The term literally means self-eating, and it's your cell's way of cleaning house. During autophagy, your cells identify and eliminate damaged components, broken proteins and dysfunctional organelles. This cellular cleanup is so important that the scientist who discovered its mechanisms won the Nobel Prize in 2016.
Kris Harris:Fasting also triggers significant hormonal changes beyond just insulin reduction. Growth hormone levels increase substantially, sometimes by as much as five-fold. This hormone helps preserve muscle mass and promotes fat burning during your fasting period. Meanwhile, norepinephrine levels rise, which helps break down fat cells for energy use. Another fascinating change involves inflammation markers and oxidative stress. Research shows that various markers of inflammation decrease during fasting periods. Your body also upregulates antioxidant defenses and DNA repair mechanisms, potentially reducing cellular damage. The gut also gets a break during fasting, which emerging research suggests might benefit the gut microbiome and intestinal stem cell function. Some studies show that intermittent fasting can increase microbial diversity and reduce gut permeability, factors linked to better overall health. On the cognitive side, fasting increases the production of brain-derived neurotrophic factor, or BDNF, a protein that supports existing neurons and encourages new neuron growth. Some researchers have compared BDNF to fertilizer for the brain, and low levels are associated with various neurological issues. While all these mechanisms are impressive, it's important to note that much of the research is still evolving. Many studies have been conducted on animals rather than humans, and the human studies often involve small sample sizes or specific populations. The duration and type of fasting protocol also significantly influence which mechanisms activate and to what degree. That said, the scientific consensus is growing that periodic fasting does trigger unique biological processes that don't occur in the typical fed state, processes that may have significant implications for health, disease prevention and possibly even longevity.
Kris Harris:Now let's separate fact from fiction when it comes to the health benefits of intermittent fasting. With all the buzz around this eating pattern, it's easy to get caught up in extraordinary claims, but what does the research actually show? Weight management is perhaps the most well-established benefit. Multiple studies have demonstrated that intermittent fasting can be an effective strategy for weight loss, with participants typically losing 3 to 8 percent of their body weight over periods of 3-24 weeks. The mechanism is fairly straightforward by restricting the eating window, most people naturally consume fewer calories. Additionally, the hormonal changes we discussed earlier, particularly the decrease in insulin and increase in norepinephrine, enhance your body's ability to burn fat. But here's where we need to separate fact from fiction. Despite what some proponents claim, intermittent fasting isn't magically superior to other calorie reduction approaches. When calories are controlled, if you consume the same number of calories during your eating window that you would have eaten throughout the day, you likely won't see significant weight loss.
Kris Harris:Moving on to metabolic health, this is where the evidence gets particularly interesting. Multiple studies show that intermittent fasting can reduce insulin resistance and lower fasting blood sugar levels by 3 to 6 percent, while fasting insulin can be reduced by 20-31 percent. These improvements can occur independent of weight loss, suggesting that fasting itself may directly benefit metabolic health. Blood lipid profiles also tend to improve with intermittent fasting. Research has documented reductions in LDL cholesterol, total cholesterol, triglycerides and inflammatory markers. For people with prediabetes or metabolic syndrome, these improvements can be substantial enough to reduce risk factors for heart disease.
Kris Harris:Now let's address one of the most exciting but also most overhyped aspects of intermittent fasting longevity. Animal studies have shown impressive lifespan extensions, with various fasting protocols sometimes increasing lifespan by 30% or more. However and this is a big however we simply don't have long-term human studies to confirm these effects in people. What we do have is evidence of cellular and molecular changes that are associated with longer lifespan, such as reduced oxidative damage, improved cellular repair processes and the autophagy we discussed earlier. We also see reductions in factors associated with age-related diseases, including cancer, neurodegenerative disorders and cardiovascular disease. But here's where I need to be absolutely clear. Claiming that intermittent fasting will definitely extend your life by X number of years is fiction, not fact. The research is promising, but preliminary when it comes to humans. Other benefits, with moderate scientific support, include improved brain health and reduced inflammation. Some studies suggest intermittent fasting may enhance cognitive function and protect against neurodegenerative diseases, while others show reductions in inflammatory markers throughout the body.
Kris Harris:Now for some of the more exaggerated claims you might encounter. Despite what some enthusiasts might tell you, intermittent fasting is not a cure for cancer. Although some preliminary research suggests it might enhance certain cancer treatments, it's not going to detoxify your body. Your liver and kidneys handle that job quite efficiently already, and it won't completely reset your metabolism or magically heal all health conditions. The bottom line is that intermittent fasting offers several evidence-based benefits, particularly for weight management and metabolic health. The potential longevity and disease prevention benefits are supported by compelling biological mechanisms and animal research, but we need more long-term human studies before making definitive claims. Remember, health interventions rarely provide universal benefits. Individual responses to intermittent fasting vary widely, based on genetics, lifestyle, existing health conditions and the specific fasting protocol followed.
Kris Harris:Let's tackle some of the most common misconceptions about intermittent fasting head-on. There's a lot of misinformation out there and it's important to separate myth from reality. First, the muscle loss concern. Many people worry that fasting will cause their hard-earned muscle to waste away. The research tells a different story. When fasting is done properly and isn't extreme, your body actually preserves muscle mass surprisingly well. This is because during shorter fasting periods, your body primarily burns stored fat, while elevated growth hormone levels help protect your muscles. However, context matters here. If you're fasting for very extended periods, not consuming adequate protein during your eating windows or not engaging in resistance training, then, yes, muscle loss becomes a greater risk. The takeaway is that most intermittent fasting protocols, when combined with proper nutrition and exercise, won't significantly impact your muscle mass.
Kris Harris:Another pervasive myth is that fasting crashes or damages your metabolism. You've probably heard that skipping meals puts your body in starvation mode, permanently slowing your metabolic rate. The evidence doesn't support this claim. Short-term fasting actually increases metabolic rate slightly due to the release of norepinephrine. Even longer fasts don't show the dramatic metabolic slowdown many fear. Any reduction in metabolic rate during fasting is primarily due to the simple fact that you're carrying less body weight, which requires less energy to maintain. Once fasting ends, metabolic rates typically normalize.
Kris Harris:The breakfast is the most important meal. Myth also deserves addressing. While this has been conventional wisdom for decades, research doesn't strongly support the notion that skipping breakfast is inherently harmful. For many people practicing 16 or 8 intermittent fasting, breakfast is skipped without negative consequences. This is highly individual, though. Some people genuinely function better with breakfast, while others do fine without it. Many also believe that fasting causes hypoglycemia or dangerous blood sugar crashes. For most healthy individuals, this isn't the case. Your body is remarkably adept at maintaining blood glucose levels through processes like gluconeogenesis, where it creates glucose from non-carbohydrate sources. People with diabetes or other blood sugar regulation issues should approach fasting more cautiously, however, and always with medical supervision.
Kris Harris:Perhaps the most dangerous misconception is that intermittent fasting is suitable for everyone. This simply isn't true. Pregnant or breastfeeding women, children and teenagers, those with a history of eating disorders, people with certain medical conditions like diabetes, and individuals on specific medications should be extremely cautious about fasting or avoid it altogether. Fasting isn't a one-size-fits-all approach, despite how it's often presented in popular media. Finally, there's the myth that you can eat whatever you want during your eating window and still reap all the benefits of fasting. Unfortunately, nutrition quality still matters significantly. Consuming primarily processed foods, even within a restricted eating window, is unlikely to yield optimal health benefits. The composition of your diet continues to play a crucial role in your overall health, regardless of when you eat. Now that we understand the facts versus fiction about intermittent fasting, let's discuss who might benefit from this eating pattern and, more importantly, who should avoid it altogether.
Kris Harris:Intermittent fasting may be particularly beneficial for those struggling with weight management issues. People with excess body fat, especially around the abdominal area, often respond well to time-restricted eating patterns. The structured approach can help reduce overall calorie intake while potentially improving metabolic markers related to obesity. Individuals with insulin resistance or prediabetes might also see significant benefits. The fasting periods can help improve insulin sensitivity, potentially reducing blood sugar levels and decreasing the risk of developing type 2 diabetes. Some studies have shown remarkable improvements in these metrics within just a few weeks of intermittent fasting. Those looking to simplify their eating routine often appreciate intermittent fasting as well. By reducing the number of meals and eating occasions, some people find they spend less time planning, preparing and thinking about food. This can create a more straightforward approach to nutrition that fits better into busy lifestyles. People interested in longevity and cellular health might be drawn to intermittent fasting for its potential autophagy-promoting effects. Though the research in humans is still developing, the cellular cleaning mechanisms triggered during fasting periods are intriguing from a long-term health perspective.
Kris Harris:However, intermittent fasting is absolutely not appropriate for everyone, and certain groups should avoid it entirely. Pregnant and breastfeeding women should not practice intermittent fasting. These life stages require consistent nutrition to support both mother and child, and restricting eating windows could compromise essential nutrient intake. Children and adolescents should also avoid intermittent fasting. Young bodies need regular nutrition to support proper growth and development. Restricting eating windows during these critical developmental years could potentially interfere with normal growth patterns. Anyone with a current or past eating disorder should approach fasting with extreme caution, if at all. The structured restriction of eating times can potentially trigger disordered eating patterns or thoughts. The psychological relationship with food is paramount, and intermittent fasting could exacerbate underlying issues.
Kris Harris:Those with certain medical conditions must be careful too. People with diabetes, particularly type 1, should only consider intermittent fasting under close medical supervision, as it can affect blood sugar management and insulin requirements. Individuals with advanced liver or kidney disease, compromised immune function or frailty should generally avoid fasting protocols. People taking certain medications that require food for proper absorption or that affect blood sugar levels need to be especially cautious. Some medications can cause dangerous drops in blood sugar when taken without food. Highly active individuals, especially competitive athletes, may find that fasting interferes with performance, recovery and training adaptations. The energy demands of intense training often align poorly with significant food restriction periods. Finally, those with a history of hypoglycemia or blood sugar regulation issues should approach fasting with caution and appropriate medical oversight. The same applies to people with a history of adrenal dysfunction or cortisol dysregulation. The bottom line is that intermittent fasting is a tool that can benefit some people while potentially harming others. It's not a universal recommendation and individual circumstances matter tremendously. When in doubt, consulting with healthcare providers before starting any fasting regimen is always the wisest approach.
Kris Harris:Let's talk about how to actually implement intermittent fasting in your daily life. If you've decided it might be right for you, starting gradually is key. Don't jump straight into extended fasting periods. If you've been eating every few hours your entire life, begin by extending your overnight fast slightly. Maybe push breakfast back by an hour every few days until you reach your desired fasting window. Choosing the right method is crucial for success. For success, the 16.8 approach, where you fast for 16 hours and eat within an 8-hour window, is often the most sustainable starting point. This might mean eating between noon and 8 pm, which for many people just means skipping breakfast. If that seems daunting, try 14.10 or even 12.12. First. The 5.2 method, where you eat normally five days a week and restrict calories significantly two non-consecutive days, works better for those who prefer having mostly normal eating days. Timing your fasting window strategically can make adherence much easier. Consider your social life, work schedule and when you naturally feel hungriest. Many find it easiest to skip breakfast rather than dinner, since dinner often has social importance. Others discover they sleep better when they finish eating earlier in the evening, perhaps by 6 pm.
Kris Harris:Managing hunger is perhaps the biggest challenge when hunger strikes during fasting periods. Try drinking water, unsweetened coffee or tea, all permissible during fasts and often surprisingly effective at blunting hunger pangs. Staying busy helps too. Hunger often intensifies when you're bored or thinking about food. Plan engaging activities during typical hunger periods. Hydration deserves special attention. When fasting Without food, you lose the water content normally found in meals, so deliberate hydration becomes more important. Aim for at least 2-3 liters of water daily. Add a pinch of salt if you're fasting for longer periods to maintain electrolyte balance, especially if you exercise.
Kris Harris:When it comes to breaking your fast, how you do it matters significantly. Avoid large heavy meals immediately after fasting, which can cause digestive discomfort. Start with something moderate in size containing protein and healthy fats. Some people find that a small handful of nuts or a boiled egg works well as a gentle transition. Nutrition quality remains crucial during eating windows. Nutrition quality remains crucial during eating windows.
Kris Harris:Intermittent fasting isn't a license to eat poor-quality foods just because you're eating less often. Focus on nutrient-dense whole foods, plenty of vegetables, adequate protein, healthy fats and appropriate portions of complex carbohydrates. Remember, you're trying to get all your daily nutrients in fewer meals, so each meal needs to carry more nutritional weight. Exercise timing may need adjustment when fasting. Some people perform well exercising in a fasted state, particularly for low to moderate intensity activities. Others need to align workouts with their eating windows. Experiment to find what works for your body, but be willing to adjust if performance suffers. Track your progress beyond just weight. Notice changes in energy levels, concentration, hunger patterns and mood. These non-scale victories often provide better indicators of how intermittent fasting is affecting your health than wait alone. Finally, be flexible and patient. Some days will be easier than others. Special occasions, travel or illness might temporarily interrupt your fasting schedule. That's completely normal and doesn't indicate failure. The goal is consistency over time, not perfection. Every day.
Kris Harris:I've been practicing intermittent fasting on and off for about three years now, and it's been quite the journey, with plenty of highs and lows. When I first started with the 16-8 method, I remember those initial mornings were challenging. I'd been a habitual breakfast eater my entire life and that first week of pushing my first meal to noon felt like my stomach was staging a revolution. But surprisingly, by week two those morning hunger pangs had substantially diminished. What I found most interesting was how my energy levels actually improved. Before intermittent fasting I was experiencing that mid-afternoon crash almost daily. Now I find my energy stays much more consistent throughout the day. My focus improved too, especially during those morning hours when I'm fasting. There's something remarkably clear about my thinking when I'm not digesting food. Not everything was smooth sailing, though. Social situations presented real challenges. I remember a team breakfast meeting where everyone was enjoying pancakes and eggs while I nursed my black coffee. The questions and sometimes concerned looks from colleagues made me realize how deeply eating patterns are woven into our social fabric.
Kris Harris:I've spoken with several friends who've tried intermittent fasting as well. My friend, sarah, found it transformed her relationship with food entirely. She noticed she stopped eating out of boredom or emotion and began truly appreciating meals After decades of mindless snacking. She described it as finally understanding what actual hunger feels like versus just wanting to eat. Then there's Michael, who had to abandon his intermittent fasting experiment after a month. Despite giving it a fair shot, he found himself obsessing unhealthily about food during fasting periods, which triggered some past disordered eating patterns. His experience is an important reminder that what works wonderfully for one person might be detrimental for another. Another colleague, jen, discovered an unexpected benefit saving time. She talks about how much more productive her mornings became without planning, preparing and cleaning up after breakfast. For her busy lifestyle as a single mom, reclaiming that time proved as valuable as any health benefit.
Kris Harris:I've cycled between strict adherence and more relaxed periods, with intermittent fasting. During high-stress times I've found forcing a fasting schedule sometimes added unnecessary pressure. Learning to adapt my fasting schedule to life's natural rhythms, being stricter when it feels supportive and looser when it doesn't, has been key to making it sustainable long term. As we wrap up today's episode on intermittent fasting, let's review what we've covered.
Kris Harris:Intermittent fasting isn't simply a diet. Fasting let's review what we've covered. Intermittent fasting isn't simply a diet. It's a pattern of eating that cycles between periods of consuming food and abstaining from it. We've explored various methods, like the popular 16-8 approach, the 5.2 method and eat-stop-eat, each offering different ways to incorporate fasting into your lifestyle. We've looked at how fasting is deeply rooted in human history, from our evolutionary past to religious traditions across cultures.
Kris Harris:The science behind intermittent fasting is compelling, with research showing potential benefits for metabolic health, cellular repair through autophagy and hormone regulation that may support weight management and overall health. However, what's most important to remember is that nutrition is not one-size-fits-all. Your body's needs are unique, influenced by your genetics, lifestyle, health status and even personal preferences. What works wonderfully for one person might be completely unsuitable for another, as we saw in the personal stories. Shared Power to take your health and wellness journey to the next level.
Kris Harris:Remember, every small step counts, and I'm here to support you every step of the way. If you enjoyed today's episode, I'd love for you to share it with your friends and family and, if you're feeling generous, consider donating at the link provided in the description. Your support helps us to keep bringing you the Corecast every week, packed with valuable insights and expert advice For more resources, tips and updates. Don't forget to visit our website at www. k ore-fit. com and follow us on Instagram at korefit tness AZ. Join our community and let's continue this journey together. Until next time, stay healthy, stay happy and keep striving for your best self. This is Kris Harris signing off from the Kore Kast, and I'll see you next week.
