Intermittent Fasting PDF

Intermittent Fasting: The backstory on intermittent fasting IF as a weight loss approach has been around invarious forms for ages, but was highly popularized in 2012 by BBC broadcast journalist Dr. Michael Mosley’s TV documentary Eat Fast, Live Longer and book The Fast Diet, followed by journalist...

Intermittent Fasting: The backstory on intermittent fasting IF as a weight loss approach has been around invarious forms for ages, but was highly popularized in 2012 by BBC broadcast journalist Dr. Michael Mosley’s TV documentary Eat Fast, Live Longer and book The Fast Diet, followed by journalist Kate Harrison’s book The 5:2 Diet based on her own experience, and subsequently by Dr. Jason Fung’s 2016 bestseller The Obesity Code. IF generated a steady positive buzz as anecdotes of its effectiveness proliferated. As a lifestyle-leaning research doctor, I needed to understand the science. The Obesity Code seemed the most evidence-based summary resource, and I loved it. Fung successfully combines plenty of research, his clinical experience, and sensible nutrition advice, and also addresses the socioeconomic forces conspiring to make us fat. He is very clear that we should eat more fruits and veggies, fiber, healthy protein, and fats, and avoid sugar, refined grains, processed foods, and for God’s sake, stop snacking. Check, check, check, I agree. The only part that was still questionable in my mind was the intermittent fasting part Intermittent fasting and weight loss: IF makes intuitive sense. The food we eat is broken down by enzymes in our gut and eventually ends up as molecules in our bloodstream. Carbohydrates, particularly sugars and refined grains (think whiteflours and rice), are quickly broken down into sugar, which our cells use for energy. If our cells don’t use itall, we store it in our fat cells as, well, fat. But sugar can only enter our cells with insulin, a hormone made in the pancreas. Insulin brings sugar into the fat cells and keeps it there. Between meals, as long as we don’t snack, our insulin levels will go down and our fat cells can then release their stored sugar, to be used as energy. We lose weight if we let our insulin levels go down. The entire idea of IF is to allow the insulin levels to go down far enough and  2 for long enough that we burn off our fat. Intermittent fasting can be hard… but maybe it doesn’t have to beInitial human studies that compared fasting everyother day to eating less every day showed that both worked about equally for weight loss, though people struggled with the fasting days. So, I had written off IF as no better or worse than simply eating less, only far more uncomfortable. My advice was to just stick with the sensible, plant- based, Mediterranean-style diet. New research is suggesting that not all IF approachesare the same and some are actually very reasonable, effective, and sustainable, especially when combinedwith a nutritious plant-based diet. We have evolved to be in sync with the day/night cycle, i.e., a circadian rhythm. Our metabolism has adapted to daytime food, nighttime sleep. Nighttime eating is well associated with a higher risk of obesity,as well as diabetes. Based on this, researchers from the University of Alabama conducted a study with a small group of obese men with prediabetes. They compared a form of intermittent fasting called “early time-restricted feeding,” where all meals were fit into an early eight- hour period of the day (7 am to 3 pm),or spread out over 12 hours (between 7 am and 7 pm). Both groups maintained their weight (did not gain or lose)but after five weeks, the eight- hours group had dramatically lower insulin levels and significantly improved insulin sensitivity, as well as significantly lower blood pressure. hours group also had significantly decreased appetite. They weren’t starving. Just changing the timing of meals, by eating earlier in the day and extending the overnight fast, significantly benefited metabolism Chapter (2): Recent Diet Trends  3 even in people who didn’t lose a singlepound. But why does simply changing the timing of our meals to allow for fasting make a difference in our body? An in-depth review of the science of IF recently published in New England Journal of Medicine sheds some light. Fasting is evolutionarily embedded within our physiology, triggering several essential cellular functions. Flipping the switch froma fed to fasting state does more than help us burn calories and lose weight. The researchers combedthrough dozens of animal and human studies to explain how simple fasting improves metabolism, lowering blood sugar; lessens inflammation, which improves a range of health issues from arthritic pain to asthma; and even helps clear out toxins and damaged cells, which lowers risk for cancer and enhances brain function. The article is deep, but worth a read. I was very curious about this, so I asked the opinion of metabolic expert Dr. Deborah Wexler, Director of the Massachusetts General Hospital Diabetes Center and associate professor at Harvard Medical School. Here is what she told me. “There is evidence to suggest that the circadian rhythm fasting approach, where meals are restricted to an eight to 10- hour period of the daytime, is effective,” she confirmed, though generally she recommends that people “use an eating approach that works for them and is sustainable to them” Chapter (2): Recent Diet Trends  4 So, here’s the deal. There is some good scientific evidence suggesting that circadian rhythm fasting, when combined with a healthy diet and lifestyle, can be a particularly effective approach to weight loss, especially for people at risk for diabetes. people with advanced diabetes or who are on medications for diabetes, people with a history of eating disorders like anorexia and bulimia, and pregnant or breastfeeding women should not attempt intermittent fasting unless under the close supervision of a physician who can monitor them. 4 ways to use this information for better health: Avoid sugars and refined grains. Instead, eat fruits, vegetables, beans, lentils, whole grains, lean proteins, and healthy fats (a sensible, plant-based, Mediterranean-style diet). 1. Let your body burn fat between meals. 2. Be active throughout your day. 3. Build muscle tone 4. Avoid snacking or eating at night time, all the time. Consider a simple form of intermittent fasting. Limit the hours of the day when you eat, and for best effect, make it earlier in the day (between 7 am to 3 pm, or even 10 am to 6 pm, but definitely not in the evening before bed. Intermittent fasting interventions for treatment of over weight and obesity in adults: a systematic review and meta-analysis. JBI Database of Systematic Reviews and Implementation Reports, February 2018. Early Time-Restricted Feeding Improves Insulin Sensitivity, Blood Pressure, and Oxidative Stress Even without Weight Loss in Men with Prediabetes. Cell Metabolism, May 2018. The Mechanism: Chapter (2): Recent Diet Trends  5 (Affecting on your Cells and Hormones) When you fast, several things happen in your body on the cellular and molecular level. For example, your body adjusts hormone levels to make stored body fat more accessible. Your cells also initiate important repair processes and change the expression of genes. Here are some changes that occur in your body whenyou fast: Human Growth Hormone (HGH): The levels of growth hormone skyrocket, increasing as much as 5- fold. This has benefits for fat loss and muscle gain. Insulin: Insulin sensitivity improves and levels of insulin drop dramatically. Lower insulin levels make stored body fat more accessible. Cellular repair: When fasted, your cells initiate cellular repair processes. This includes autophagy, where cells digest and remove old and dysfunctional proteins that build up inside cells. Gene expression: There are changes in the function of genes related to longevity and protection against disease. These changes in hormone levels, cell function and gene expression are responsible for the healthbenefits of intermittent fasting. Mech anistic Factors Linking Intermittent Fasting with Health: Figure 1 illustrates how factors hypothesized to link intermittent fasting with health outcomes are related. Briefly, intermittent fasting regimens are hypothesized to influence metabolic regulation via effects on circadian biology, the gastrointestinal micro biota, and modifiable lifestyle behaviors. Negative perturbations in these systems can produce a hostile metabolic milieu, which predisposes individuals to the development of obesity, diabetes, cardiovascular disease, and cancer. See Chapter (2): Recent Diet Trends  6 recent review by Longo and Mattson for a detailed review of the molecular mechanisms potentially linking fasting with health outcomes. Who Should Be Careful or Avoid It? Intermittent fasting is certainly not for everyone. If you’re underweight or have a history of eating disorders, you should not fast without consulting with a health professional first. In these cases, it can be downright harmful. Safety and Side Effects Hunger is the main side effect of intermittent fasting. You may also feel weak and your brain may not perform as well as you're used to. This may only be temporary, as it can take some time for your body to adapt to the new meal schedule. If you have a medical condition, you should consult with your doctor before trying intermittent fasting. This is particularly important if you: Have diabetes. Chapter (2): Recent Diet Trends  7 Have problems with blood sugar regulation.Have low blood pressure. Take medications.Are underweight. Have a history of eating disorders. Are a woman who is trying to conceive. Are a woman with a history of amenorrhea.Are pregnant or breastfeeding. All that being said, intermittent fasting hasan outstanding safety profile. There is nothing dangerous about not eating for a while if you’re healthy and well- nourishedoverall. Liquids during Fasting: Water, coffee, tea and other non-caloric beverages are fine. Do not add sugar to your coffee. Small amounts of milk or cream may be okay.Coffee can be particularly beneficial during a fast, as it can blunt hunger. Diet Plan Example: Here's an idea of what to eat (and when to eat it) ona 16:8 fasting diet, depending on which eating window you choose: Early eating window meal plan 8 a.m.: egg and veggie scramble, side of whole-graintoast 10 a.m.: yogurt and granola 12 p.m.: chicken and veggie stir fry Evening decaf tea Midday eating window meal plan Morning black coffee or tea (no cream or sugar) 11 a.m.: banana peanut butter smoothie Chapter (2): Recent Diet Trends  8 2 p.m.: avocado toast with pistachios 4 p.m.: dark-chocolate-covered almonds 6 p.m.: turkey meatballs and tomato sauce overwhole wheat (or zucchini noodle) pasta Late eating window meal plan Morning black coffee or tea (no cream or sugar) 1 p.m.: blackberry chia pudding 4 p.m.: black bean quesadilla (cheese of your choice,black beans, bell pepper, and taco seasoning) 6 p.m.: banana 9 p.m.: grilled salmon, vegetables, and quinoa. Conclusion: Even a single bout of fasting can have positive effects, but temporary behavior changes only produce temporary results. It is more important to focus on finding a healthy diet plan that you cansustain long-term. You should also look for an eating pattern that reduces or eliminates nighttime eating. Some people may find this method easier to follow than a standard “don’t eat this or that” diet because it doesn’t restrict the type of food eaten. Others may choose to layer in a food-specific diet into their fasting plan for greater success. The conclusion is that while more human studies are needed, time- restricted intermittent fasting as a lifestyle may be the best approach for long-term weight control.Association of intermittent fasting with intestinal micro biota, circadian clock, and other lifestyle factors hypothesized to result in metabolic regulation and downstream impacts on obesity, type 2 diabetes (T2D), cancer, and cardiovascular disease (CVD). Chapter (2): Recent Diet Trends  9 Sustainable weight management and wellbeing Prioritising a healthy lifestyle and sustainable weight management is crucial in our fast-paced world. Amidst countless diet fads and trends, the 5:2 Diet stands out for its simplicity, flexibility, and potential health benefits. What is the 5:2 Diet? The 5:2 diet, also known as the Fast Diet, is an intermittent fasting plan aimed at promoting weight loss and overall wellbeing. The concept is simple: eat a healthy diet for five days, incorporating lots of vegetables, whole grains, beans, nuts, fish and fruits as a dessert and on the remaining two days, significantly reduce calorie intake. Unlike traditional diets focusing on daily caloric restriction, the 5:2 diet allows for a more flexible approach to eating. Ideally, during the two fasting days, you should consume no more than 500-600 calories for women and 600-800 calories for men. In one of our studies, we employed a strategy involving the consumption of non-starchy raw or cooked vegetables for both lunch and dinner, complemented with 2 tablespoons of extra- virgin olive oil, vinegar, lemon, and spices. This caloric reduction prompts the body to use its fat stores for energy, resulting in gradual weight loss over time. But don’t panic, the fasting days don’t need to be consecutive, allowing for breaks in between if desired. Benefits of the healthy 5:2 Diet Weight management Sustainable weight management is where the 5:2 diet comes into its own. Recent studies reveal that overweight individuals following this plan can shed an average of 8 percent body weight and 16 percent body fat in just six months. Unlike overly strict diets that can be challenging to maintain, the 5:2 diet offers a realistic option. You can enjoy regular, healthy meals for most of the week, avoiding the feelings of deprivation, and only fast for 2 days. Some people find this intermittent fasting plan easier and conducive to sticking to their goals. Type 2 diabetes Chapter (2): Recent Diet Trends  10 Scientific studies show that, when combined with the consumption of healthy food on both regular and fasting days, the 5:2 diet can improve how your body handles glucose and insulin. And that's good news, because it could mean a lower chance of developing type 2 diabetes and its terrible complications, such as heart and kidney disease, as well as eye and nerve issues related to diabetes. Heart health Numerous studies in humans have shown that intermittent fasting can also lower blood pressure and improve blood lipid levels, which are significant factors in heart disease risk. However, it's worth noting that one study discovered that intermittent fasting led to an increase in LDL-cholesterol levels. This underscores the importance of maintaining a high-quality diet on non-fasting days. Brain health Here's something potentially fascinating about the 5:2 diet: it is not just about losing weight; it might also give your brain a bit of a boost! Some animal studies are suggesting that intermittent fasting, like the 5:2 plan, could help with focus and memory. We are still learning more about how this works in humans, but it is definitely something worth keeping an eye on. A healthy plan The ‘Healthy 5:2 Diet’ stands out for its user-friendly approach and adaptability to any schedule. The flexibility to choose fasting days is a major plus. While we await more specific research in humans, it's evident that the 5:2 diet could offer benefits beyond weight loss, as long as you maintain a diet rich in healthy, unprocessed foods and engage in regular exercise. Making healthy choices can make a big difference in your health, no matter how old you are or if you already have health issues. Starting early is great, but it's never too late to make positive changes. Eating better, staying active, and keeping your mind engaged through activities can bring benefits, even if you're just starting now in your 50s, 60s, or 70s. It's a step towards a healthier, longer life. Chapter (2): Recent Diet Trends  11 A nutritious and delicious crab and avocado salad Healthy 5:2 Diet recipe suggestions: For fasting days Breakfast | Overnight bulgur with cinnamon, apples and walnuts Lunch | Chopped salad with crab meat and avocado lime dressing Dinner | Minestrone with wholemeal penne and parmesan Chapter (2): Recent Diet Trends