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Intermittent Fasting vs The Zone Diet

Abstaining from food and beverage, other than water, for a period of time (a.k.a fasting) has been used since the beginning of time out of necessity for survival, spiritual reasons, and health promotion. Intermittent Fasting (IF) is an eating pattern that goes between days of fasting or partial fasting and eating. IF has become increasing popular in the health and fitness arena for its perceived role in weight loss and improved health. Here we’ll tell you more about it and give you Dr. Sears’ take on this old concept but new trend.

What is Intermittent Fasting?

Calorie restriction is the reduction of calorie intake without compromising nutrition. Calorie restriction has been shown to be the most effective way to help slow down the aging process. A recent study showed that restricting calories over a two year period of time slowed metabolism and reduced oxidative stress, two key pieces for reducing the rate of aging and protecting against age-related disease (1).  Intermittent fasting (IF) tries to replicate the benefits of calorie restriction, without having to continuously restrict calories. The idea being that not restricting calories daily makes compliance easier to follow. IF involves restricting calories 1-3 days per week and then eating as you normally would on your non-restricted days. There are several approaches to Intermittent Fasting but the premise is you eat normally a few days a week and drastically cut back on calories the other days.

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This form involves a day in which food and beverages (other than water) are completely restricted followed by a day where foods and beverages can be consumed normally. There are variations within alternate day fasting as well. A more scientifically investigated form involves eating 25 percent of your needed calories on one day and then 125 percent of your needed calories on the next day. The total calorie intake would be 75 percent of needed calories (2).

Modified Fasting Regimens

Some calories can be consumed on fast days but it’s severely restricted to 20-25% of your energy needs (approximately 500-600 calories). This is the basis for the 5:2 diet where you restrict energy two non-consecutive days and then eat normally the other 5 days.

Time Restricted Feeding

This involves daily fasting intervals ranging from 12-20 hours. Religious fasts often use time-restricted feeding (i.e. Ramadan).

The Science

The science on calorie restriction (CR) itself is strong, but what about using the IF approach to calorie restriction? Many of the benefits of intermittent fasting such as improved metabolic profiles, decreased weight and reduced risk for chronic disease have been widely studied in animals. Despite the success of those studies, the same benefits are mixed when it comes to human trials (3), which may be related to compliance. In studies comparing similar caloric intake using both IF and CR there are no differences between the two groups in either weight loss, improvements in blood markers (glucose, insulin, lipids, inflammation) and chronic disease risk (4). Both may be equally effective for weight loss and cardio-protection. In one series of carefully controlled long-term trials (the CALERIE studies), the goal was to have individuals reduce calorie intake by 25 percent on a continuous basis. Even though individuals could only reduce their intake by 15% these calorie restricted (CR) experiments demonstrated significant clinical benefits (1). The data is clear that if you can restrict calories there are benefits to be gained.

Intermittent Fasting vs. The Zone Diet

Intermittent fasting is based on the idea that continuous calorie restriction is too hard to follow for the lifetime. So maybe you can do it for a couple of days with fasting or mini-fasts, knowing you can eat normally or overeat the next day or every other day. Regardless of the approach used, the answer appears to be that there is no benefit of intermittent fasting compared to consuming the same number of restricted calories day in and day out according to recent studies. Furthermore, there is no difference in weight loss between a continuous calorie–restricted diet and an intermittent fasting diet because the weekly intake of calories consumed is about the same. However, subjects in these studies using intermittent fasting tend to be less compliant as they are hungrier on their fasting days. The key to the Zone Diet is not simply the restriction of calories, but the constant maintenance of hormonal balance that results in stable blood glucose levels so that you are not hungry between meals.  After all,  who wants to be hungry no matter what the potential health benefits may be. In addition, if you use Ramadan as an example in which observant Muslims who fast all day and then only eat after the sun goes down, you see that they do lose weight, but the lost weight is all regained shortly after the fasting period is over.  This isn’t ideal for long-term health benefits. In addition 16 hour fasts may place stress on your bodies hormonal systems as one may run the risk of upsetting the hormonal levels like insulin, glucagon, and cortisol.

The Zone Diet is built upon the concept of calorie restriction coupled with hormonal balance, so that you are never hungry or fatigued and can easily follow it for a lifetime. Following a calorie restricted Zone Diet will yield many of the clinical positive benefits often attributed to various  forms of fasting but with greater long-term compliance.{{cta('a8225404-c675-40b7-8eaa-4836beb805da')}}

References:

1. Leanne M. Redman, Steven R. Smith, Jeffrey H. Burton, Corby K. Martin, Dora Il'yasova, Eric Ravussin. Metabolic Slowing and Reduced Oxidative Damage with Sustained Caloric Restriction Support the Rate of Living and Oxidative Damage Theories of Aging. Cell Metabolism, 2018.
2. Trepanowski JF, Kroeger CM, Barnosky A, Klempel MC, Bhutani S, Hoddy KK, Gabel K, Freels S, Rigdon J, Rood J, Ravussin E, Varady KA. Effect of Alternate-Day Fasting on Weight Loss, Weight Maintenance, and Cardioprotection Among Metabolically Healthy Obese Adults: A Randomized Clinical Trial. JAMA Intern Med. 2017 Jul 1;177(7):930-938. 
3. Horne BD, Muhlestein JB, Anderson JL. Health effects of intermittent fasting: hormesis or harm? A systematic review.Am J Clin Nutr. 2015 Aug;102(2):464-70. 
4. Patterson RE, Laughlin GA, LaCroix AZ, Hartman SJ, Natarajan L, Senger CM, Martínez ME, Villaseñor A, Sears DD, Marinac CR, Gallo LC.Intermittent Fasting and Human Metabolic Health. J Acad Nutr Diet. 2015 Aug;115(8):1203-12 

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Dr. Sears Q&A: Weight Loss

With so much interest in weight loss and so much buzz around weight loss drugs, we put together some of the top questions we get in this latest Q&A blog. Here Dr. Sears answers your questions on weight loss, weight loss drugs and what he thinks is the most scientifically backed way to lose weight. See what he has to say.Question: What medical conditions could impede weight loss, and how can they be identified?  Answer:  Any condition associated with insulin resistance will make it difficult to lose weight.  This would include diabetes, heart disease, neurological disease, etc.  Also, any drug that induces insulin resistance will also make it difficult to lose weight.  These include corticosteroids and many neurological drugs. Question: How do hormones affect weight loss, and which imbalances are most detrimental? Answer: High levels of insulin (caused by insulin resistance), high levels of cortisol (caused by stress), and low levels of satiety hormones such as GLP-1 will make weight loss difficult. Question: Is there a connection between sleep quality and weight loss? Answer: Poor quality sleep increases cortisol levels that lead to insulin resistance. The higher your level of insulin resistance, the more difficult it is for any organ to remove glucose from the blood for transport into the cell, where it can be converted to energy. This i Question: Do any weight loss supplements work?  Answer: Not really. You have to restrict calories to activate AMPK which causes your body to effectively burn excess stored body fat.   Question: What medications are FDA approved for weight loss? Answer: There are number of approved older drugs, but the most widely used is still an old drug (Phentermine) that was only recently approved for long-term use. However, the new injectable GLP-1 receptor agonists are more powerful and more popular. The scientific name for the most well-known injectable weight-loss drug is semaglutide, which is marketed under the tradenames Ozempic and Wegovy. In simple terms, these injectable drugs activate the release of the hormone GLP-1 from the gut that goes directly to the brain to tell you to stop eating. These drugs were initially developed to treat type 2 diabetes, but the clinical studies in overweight and obese individuals demonstrated significant weight loss at higher levels. Question: What are the unintended side effects of weight loss medications (i.e. GLP-1s, dual GIP/GLP-1). Answer: One major problem is that the lack of hunger caused by the drug makes you less likely to consume sufficient protein to maintain lean body mass.  Lean body mass is defined as functional tissue such as organs (including the brain) and bone.  Nearly 40 percent of the weight loss in obese patients comes from loss of lean body mass.  Without adequate protein (especially on a diet that is calorie-restricted because of lack of hunger), the replacement of damaged cells is compromised.  The skin and hair are the first site to suffer.  This lack of protein also makes it difficult to maintain mitochondrial function that provides energy for each of your 30 trillion cells. As a result, fatigue (both mental and physical) is often experienced. Question: Would you recommend an injectable weight loss drug? Answer: The answer is no. There is a big difference between weight loss and fat loss. Weight loss is the combined loss of stored body fat and lean body mass (i.e., muscle). You want to lose fat but not muscle. Although the weight loss using weekly semaglutide injections is impressive according to the literature, a deeper look shows that about 40 percent of that weight loss is due to loss of lean body mass. That is not a good sign. It suggests that the injections reduce hunger to the extent that the person has little desire to eat enough protein to maintain muscle mass. In essence, the drug increases the patients' sarcopenia (muscle loss). One of the consequences of sarcopenia is increased frailty. Also once you stop using these weight loss drugs, the weight quickly returns. Question: Does a high protein diet help with weight loss? Answer: Most high protein diets are ketogenic diets that disrupt metabolism in addition to being high fat.  The appropriate diet is protein-adequate (about 30 grams of protein at each meal), carbohydrate-moderate (primarily non-starchy vegetables, low-fat (to reduce calories) and rich in fermentable fiber.  The common name for such a diet is the Zone diet. The ideal amount of protein at each meal for weight loss is about 30 grams. Less than 30 grams of protein at meal will not generate the hormonal signals from the gut to stop hunger. Too much protein at meal, greater than 30 grams, will inhibit AMPK activity which helps cells burn excess stored fat.  

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Aging: Can You Slow It Down?

The first few weeks of the New Year are often focused on the resolve to lose weight, when in actuality people should focus their goals on slowing down aging, no matter the time of year. The only regimen that clinically achieves results in slowing the aging process is calorie restriction without malnutrition. Why? It’s not simply losing weight but orchestrating the complex interplay of reducing senescent cells, reprograming your metabolism, and changing gene expression, leading to a longer and better life.   A Timeline of Calorie Restriction   The first recorded human experiments with calorie restriction began with the written books of Luigi Cornaro in the 16th century, as I outlined in my book The Anti-Aging Zone, published in 1999. However, the molecular mechanisms of why calorie restriction is so effective required more recent breakthroughs in metabolism and epigenetics that were confirmed with the CALERIE study that carefully controlled the diets of 225 participants over two years and then ongoing testing of their retained blood samples.     The results of the CALERIE study have been impressive. However, the one clear take-home lesson was that reduction of insulin resistance was the most predictive blood marker correlated with the genetic changes and the decrease in senescent cells that ultimately accelerate aging.   The Zone on Calorie Restriction   The Zone diet is a calorie-restricted diet that was patented to reduce insulin resistance. It requires balancing macronutrients at each meal to generate the rapid hormonal changes that give rise to satiety. Only then can you follow calorie restriction for a lifetime without hunger and fatigue. It starts with having enough protein at each meal to create satiety in the brain's appetite control center. You need about 30 grams of protein (no more, but no less) at each meal to generate the same hormonal responses induced by the recent injectable weight loss drugs. However, you also must balance that protein with an adequate level of low-glycemic carbohydrates (about 40 grams) to stabilize blood glucose levels, and then add a dash of monounsaturated fat (about 15 grams). Over the years, it has been demonstrated by more than 40 research publications that the Zone diet is superior to ketogenic diets and the Mediterranean diet under controlled clinical research.    A New Technology to Slow Down Aging  Unfortunately, many people think the Zone diet requires too much thinking.  That’s why I developed Zone Foods to overcome that problem. The first generation of Zone Foods demonstrated dramatic reductions in insulin resistance compared to a control group, getting an equal number of calories (1). The second generation of Zone Foods offers greater variety and even more appetite suppression without thinking. This second generation will include new and improved versions of the Zone Pasta and Zone Bars, with new additions of Zone Muffins, Zone Oatmeal, Zone Granola, Zone Soups, and Zone Cookies (coming soon!). Each Zone Food contains 15 grams of protein, balanced with the appropriate level of low-glycemic carbohydrates, so any combination of two Zone Foods will provide the critical 30 grams of protein at a meal to stop hunger and maintain peak mental awareness for the next five hours. The growing variety of Zone Foods makes following the Zone diet incredibly easy. If you are never hungry, that indicates that you are reducing insulin resistance. The long-term benefit to you is slowing aging, which is only possible with lifelong use of Metabolic Engineering that starts with the Zone diet as its foundation. You May Also Like: Reaching the Zone Using Metabolic Engineering

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