Time-restricted eating and fasting can be effective strategies for losing weight and optimizing longevity. In conjunction with a restricted eating window, meal frequency can also play a role. Two meals a day may be optimal for individuals who are predisposed to gaining weight while people not prone to weight gain may prefer to eat three times a day. This eating pattern is powerful and uncomplicated. However, food is a meaningful part of happiness and celebration, so allowing for some flexibility in dietary patterns is important. In this clip, Dr. Valter Longo describes his approach to fasting and his philosophy that if an eating protocol is too regimented people will abandon it.
Rhonda: Do you practice fasting yourself, do you?
Valter: Yes, of course, I practice fasting, I don't normally eat lunch. But also, I just, sort of, finished a book, which was published in Italy, and it's gonna follow here in the U.S. And in it, I talk about the need to use this in a flexible way, right? And this is gonna have to be the future of nutrition, and I think nutritionists, and dietitians, and doctors are gonna have to get used to this. So that, for example, I say, if you're overweight, or obese, or you tend to gain weight, then you have to go to this two-meal-a-day program, with breakfast and lunch, or breakfast and dinner, okay, as I did for 15 years.
Then if you're underweight, you can't do that anymore, so you have to go back to three meals a day, right? So, you have to use fasting and time-restricted feeding, and such in Panda's work, which I also utilize, for that purpose, you know. So, keep the feeding to 12 hours or less, and then decide the meal frequency. And Satchin and I just wrote an article on this, and to control the weight, it's really important, particularly control, you know, visceral fat. So, we hope that that's what doctors start doing, and say, instead of...gives simple solution because two meals a day may not be easy to follow, but it's a clear rule, right? And that's what people need.
You can say, "I go for it, or I don't. But if I do go for it, it's gonna work," right? Whereas, now we have a system, where it's almost impossible for anybody to regulate. When you tell somebody, "Eats five or six times a day," it's almost impossible to regulate what somebody eats, right? By making it two meals a day, then you have a much higher control. In time restriction and two meals a day, they can serve to, you know, regulate the amount of calories as such and as shown for the time restriction. And so now, we know, we need to do more studies on meal frequency, but, of course, this is likely to get the same similar effects.
Rhonda: Do you think it's more important, so if you're eating within this 12-hour window, which is coordinated with circadian rhythm? Then if you're eating two meals, do you think that you'd get more benefits if you had the two meals closer together, because then you in theory would be fasting for longer, you'd have, you know more, beta-hydroxybutyrate, ketone bodies, things that are being produced upon a prolonged fasting?
Valter: I would say, you know, I spent, you know, almost 25 years since the Walford days, and I would say I had learned one thing. And also being Italian, and I spend a lot of time around the world, I learned that you cannot take happiness away from people, you know? So, I always stayed away from trying to regulate too much, to close, two hours apart what do you gotta eat. So, I think we always start with how can we keep you as close as possible to what makes you happy, while optimizing the longevity aspect? So, I never started doing that because I know that people are not gonna do it, just like calorie restriction. Calorie restriction has been around for 100 years, and nobody does it, right? I mean, maybe 1 in 1,000. I'll be surprised if it's even that, right? Maybe 1 in 10,000, right? So, after 100 years of calorie restriction research, 1 in 10,000 American, maybe, are doing calorie restriction. So, I think that it's important, you know? For example, with the two meals a day, there's a lot of people that have done that on their own, right?
Valter: There's a lot of centenarians if you go to Loma Linda, or you go to Okinawa, or you go to Southern Italy, a lot of people say, "Yeah, eat twice a day, that's okay." So, that told me that, from the beginning, that that was something that was doable, and people are even doing it in a voluntary way. Anything else, we start regulating, no, you should eat [inaudible 00:36:56]. And also 12 hours, I think a lot of people did that kind of time restriction, right?
You know, so when I grew up, that's how we did it, you know? Maybe at breakfast at 8:00 a.m., and then 8:00, 8:30, the most, you're finished, you know, that was it. And so, yeah, so I think that that's important not try to push for every inch of the longevity plan. Because people will abandon it, that's another thing we're sure of, you know? If you tell them to do things that are very much not in tune with what they're used to, they'll do it for six months, and then they'll never do it again.
So, you know, this is why the skipping meals because a lot of people do it, and when you switch to it, that's just an easy thing to do, and you can do a lot the rest of your life. And then, the periodic fasting-mimicking diets because also it's not very invasive, and people say, "Yeah, you know, every three or four months, I'll give you five days," like that. You know, "Make it simple for me, don't make me, you know, don't make it too low-calorie, make me eat, but I can do it." So, I think, if we want the masses to do it, it has to be the technology, and the safety, etc., etc., has to match their needs. And I think that that's where the effort should be put in, rather than trying to regulate everything, how people do everything.
Rhonda: Yeah, compliance is very important.
A chemical produced in the liver via the breakdown of fatty acids. Beta-hydroxybutyrate is a type of ketone body. It can be used to produce energy inside the mitochondria and acts as a signaling molecule that alters gene expression by inhibiting a class of enzymes known as histone deacetylases.
The practice of long-term restriction of dietary intake, typically characterized by a 20 to 50 percent reduction in energy intake below habitual levels. Caloric restriction has been shown to extend lifespan and delay the onset of age-related chronic diseases in a variety of species, including rats, mice, fish, flies, worms, and yeast.
A person who is 100 or more years old.
The body’s 24-hour cycles of biological, hormonal, and behavioral patterns. Circadian rhythms modulate a wide array of physiological processes, including the body’s production of hormones that regulate sleep, hunger, metabolism, and others, ultimately influencing body weight, performance, and susceptibility to disease. As much as 80 percent of gene expression in mammals is under circadian control, including genes in the brain, liver, and muscle. Consequently, circadian rhythmicity may have profound implications for human healthspan.
A diet that mimics the effects of fasting on markers associated with the stress resistance induced by prolonged fasting, including low levels of glucose and IGF-1, and high levels of ketone bodies and IGFBP-1. More importantly, evidence suggests these changes in the cellular milieu are associated with a sensitization of cancer cells to chemotherapeutic drugs while simultaneously also conferring greater stress resistance to healthy cells. Evidence also continues to emerge that properties of the fasting-mimicking diet, particularly its ability to cause immune cell turnover, may also make it useful in the amelioration of auto-immune diseases like multiple sclerosis.
 Cheng, Chia-Wei, et al. "Prolonged fasting reduces IGF-1/PKA to promote hematopoietic-stem-cell-based regeneration and reverse immunosuppression." Cell Stem Cell 14.6 (2014): 810-823.  Choi, In Young, et al. "A diet mimicking fasting promotes regeneration and reduces autoimmunity and multiple sclerosis symptoms." Cell Reports 15.10 (2016): 2136-2146.
Molecules (often simply called “ketones”) produced by the liver during the breakdown of fatty acids. Ketone production occurs during periods of low food intake (fasting), carbohydrate restrictive diets, starvation, or prolonged intense exercise. There are three types of ketone bodies: acetoacetate, beta-hydroxybutyrate, and acetone. Ketone bodies are readily used as energy by a diverse array of cell types, including neurons.
A type of intermittent fasting that exceeds 48 hours. During prolonged periods of fasting, liver glycogen stores are fully depleted. To fuel the brain, the body relies on gluconeogenesis – a metabolic process that produces glucose from ketones, glycerol, and amino acids – to generate approximately 80 grams per day of glucose . Depending on body weight and composition, humans can survive 30 or more days without any food. Prolonged fasting is commonly used in the clinical setting.
 Longo, Valter D., and Mark P. Mattson. "Fasting: molecular mechanisms and clinical applications." Cell metabolism 19.2 (2014): 181-192.
Restricting the timing of food intake to certain hours of the day (typically within an 8- to 12-hour time window that begins with the first food or non-water drink) without an overt attempt to reduce caloric intake. TRE is a type of intermittent fasting. It may trigger some beneficial health effects, such as reduced fat mass, increased lean muscle mass, reduced inflammation, improved heart function with age, increased mitochondrial volume, ketone body production, improved repair processes, and aerobic endurance improvements. Some of these effects still need to be replicated in human trials.
An excess of visceral fat, also known as central obesity or abdominal obesity. Visceral fat, in contrast to subcutaneous fat, plays a special role involved in the interrelationship between obesity and systemic inflammation through its secretion of adipokines, which are cytokines (including inflammatory cytokines) that are secreted by adipose tissue. The accumulation of visceral fat is linked to type 2 diabetes, insulin resistance, inflammatory diseases, certain types of cancer, cardiovascular disease, and other obesity-related diseases.
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