The Latest Science On Low-Carb Diets, Is Fasting An Eating Disorder? Should Lean Females Fast?, How To Combat Sleep Deprivation & Much More – Ben Greenfield Fitness

Check out the Ben Greenfield Fitness Episode Page & Show Notes

Key Takeaways

  • A low-carb, high-fat diet does not impair high-intensity exercise performance
  • Lift weights and use the sauna to avoid muscle loss while eating at a calorie deficit for weight loss
  • Short duration (~10 minutes), moderate-intensity exercise is best for boosting mood
  • If you’re a lean, active female be careful with time-restricted eating/intermittent fasting
    • “I don’t think lean females should avoid fasting, but my general recommendation is as follows: If you’re a lean, active female you really don’t need to be intermittent fasting longer than 12 hours”
    • Why? 
      • A regular fasting protocol (especially involving fasting periods for 12+ hours) can limit both luteinizing hormone and follicle-stimulating hormone production, resulting in a downregulation of fertility. Anytime you see a downregulation in fertility, there’s also a downregulation of things like libido and overall energy levels.
  • How far from your body should red light therapy devices, like the Joovv, be?
    • “Typically with a red light therapy device that has a power of ~100 mW/cm^2 [like the Joovv), you can get all the benefits you need in about 5-15 minutes if you are 2-6 inches away from the device”
      • There’s 0 evidence that a Joovv can cause harm by putting it right on the skin (just don’t leave it there longer than ~5-10 minute)

Relevant Products and Supplements Mentioned

Books Mentioned

Intro

  • In this episode, Ben answers listener questions and touches on some of the latest research in the world of health, nutrition, and fitness

Ben’s Morning Nootropic Cocktail

A Low-Carb, High-Fat Diet Does Not Impair High-Intensity Exercise Performance

  • Check out the study
    • It examined the effects of a 12-week, very low-carb, high-fat diet on maximal aerobic capacity, high intensity intermittent exercise, and cardiac autonomic regulation (AKA heart rate variability)
      • The experimental group was compared to a control group which followed a standard habitual diet (which consisted of a~50-60% carb intake) 
    • The key finding: 12 weeks of eating a low-carbohydrate, high-fat diet was found not to impair high-intensity exercise lasting up to 25 minutes
  • Ben comments:
    • You can’t quite say that this parallels what a hard-charging athlete would experience (they really need carbs)
      • “But for the average exercise enthusiast, this is probably a study you could take and conclude that you can eat somewhat low-carb and still get away with enhanced performance”

Lift Weights and Use the Sauna to Avoid Losing Muscle While Following a Low-Calorie Diet

  • Check out the study
    • It examined the effects of resistance training in supplement with a low-calorie + low-carb diet
    • The findings:
      • The group who did not engage in resistance training while in a calorie deficit for 12 weeks lost a good amount of total body mass
      • “Your body can hold onto muscle even in a calorie restricted state if a loading stimulus is present”
  • Ben comments:
    • “If you’re going to diet, you need to be lifting weights”
  • Ben recalls a similar study (which we couldn’t track down) which found that hyperthermia staved off muscle atrophy in people who weren’t able to lift weights while following a low-calorie diet
    • Therefore, it’s also a good idea to supplement some form of sauna (infrared or dry) while dieting
    • Caveats:
      • The study participants spent a LONG time in heat – ~2 hours
      • The study didn’t utilize a sauna – it was a custom-made heat machine (a pulse shortwave diathermy machine)
  • In conclusion:
    • “I would say that two of the very good things you could do if you’re restricting calories would be to lift weights and get in the sauna… both for muscle maintenance and to stave off muscle atrophy”

Fasting is NOT an Eating Disorder

  • A while back, the New York Times published an article titled – You Call It Starvation. I Call It Biohacking.
    • The article dove deep into the emerging popularity of eating one meal a day/intermittent fasting/time-restricted eating and explored whether this type of behavior may actually be classified as an eating disorder
  • Ben has some thoughts…
    • Of course it’s not – fasting is very common in many religious disciplines
    • “Ultimately, the pros outweighs the cons to such a great extent”
    • This article is pretty harmful
      • Quite a number of people who graze on food for 16+ hours a day might read it and vow to never try intermittent fasting/time-restricted eating for fear of being labeled as having an eating disorder by the media

Short Duration, Moderate-Intensity Exercise is Best for Boosting Mood

  • A new review looked into the optimum exercise intensity, type, and duration for boosting mood
    • The findings:
      • For boosting mood, the optimal exercise intensity is moderate (low-intensity is too dull and high-intensity is too unpleasant)
      • 10 minutes of moderate-intensity exercise was sufficient to achieve gains in mood
        • There was little evidence that exercising beyond 30 minutes led to any further gains in mood
    • The takeaway
      • It really doesn’t take much exercise to increase brain-derived neurotrophic factor (BDNF) levels in the brain and achieve some of the mood-benefiting effects of exercise

Is fasting dangerous for lean/active females?

  • Let’s get nerdy.. 
    • The hypothalamus releases gonadotropin-releasing hormone (GnRH) which then tells the pituitary gland to release both luteinizing hormone (LH) and follicle-stimulating hormone (FSH)
      • These hormones then act on the gonads (testes in men, ovaries in women)
        • In women – the production of estrogen and progesterone is stimulated
        • In men – the production of testosterone and sperm is stimulated
      • Note – the pulses of GnRH are sensitive to a variety of things (light, activity, and food)
        • There is evidence that short-term fasting can alter this hormonal pulse (in women it appears to be more pronounced)
  • So….
    • In lean females who don’t have as many fats, cholesterol, DHEA, and vitamin D to go around, a regular fasting protocol (especially involving fasting periods for 12+ hours) can actually inhibit things like menstruation and limit both luteinizing hormone and follicle-stimulating hormone production
      • This can result in a downregulation of fertility
        • Anytime you see a downregulation in fertility, there’s also a downregulation of things like libido and overall energy levels
    • “In most females, you generally see that once you get below about 12 to 13 percent body fat, some of these risk mechanisms with caloric restriction or intermittent fasting kick in”
    • “I don’t think lean females should avoid fasting, but my general recommendation is as follows: If you’re a lean, active female you really don’t need to be intermittent fasting longer than 12 hours”
  • In regards to exercise:
    • “If you are a lean, active female, I would not be doing hard exercise sessions that are catabolic during your fasted window” 
    • “For any guy who wants to put on a bunch of muscle and get maximum protein synthesis, if you’re going to use intermittent fasting, do something easy and aerobic during the fasting window and then save your hard weight training until 4-5 PM after you’ve had lunch”
    • If you’re a lean female or a guy who wants to put on muscle, do your heavy intermittent fasts on recovery days
  • Two recommendations for books on fasting:

Tactics to Help Parents of Newborns Improve Their Sleep and Combat the Effects of Sleep Deprivation

  • Tech for naps:
    • Get a NuCalm and wear it during a nap (use code: BEN500 for $500 off of the Performance or Pro model)
      • The device allows for 20 minutes of rest to be equal to a full 90-minute sleep cycle (Ben really doesn’t get into many of the details)
    • Listen to Yoga Nidra 
      • “Yoga Nidra is something that can do a pretty decent job at simulating a sleep cycle without you needing to fall asleep”
    • Use the Sleepstream app
      • It can play binural beats, pink noise, white noise etc. – all thought to boost sleep quality
  • To help you get back to sleep faster after waking up for a feeding:
    • Keep a pair of blue light blocking glasses handy – you want to avoid exposing yourself to blue light until it’s time to wake up for the day
    • Install red incandescent bulbs in the nursery (or any room you plan to use when feeding your baby in the middle of the night)
      • Why? – Red light doesn’t affect your melatonin levels
    • Use CBD (specifically a CBD vape pen)
      • Ben recommends the brand that’s linked
      • Why not sublingual CBD? – It can take a while for the effects to kick in (a vape pen is near instant)
    • If you’re electrosensitive, exposure to EMFs can make it hard to fall back asleep
      • For this reason, stay away from your Wi-Fi router (or just unplug it during the night)
  • Other suggestions:
    • Rotate nightly who wakes up to feed the baby with your partner
  • If you’re sleep-deprived and still want to exercise:
    • Research has shown short bursts of high-intensity exercise (like 10-minutes of kettlebell swings or an AirAssualt bike workout) OR longer bouts of easy aerobic endurance exercise are the two best forms of exercise to do in a sleep-deprived state
  • Supplements to combat sleep-deprivation:
    • Qualia Mind or Qualia Focus
      • “If you’re sleep deprived, with 5 capsules of Qualia Focus or 7-8 capsules of Qualia Mind you can charge hard for 6-8 hours”
    • Modafinol can also work

How far from your body should red light therapy devices, like the Joovv, be?

  • The background:
    • Some of the benefits of red-light therapy include:
      • Increased production of collagen
      • Increased circulation and better oxygen delivery to tissues
      • Epidermis repair (removal of stretch marks, scar tissue, or cellulite)
      • For more, check out these Podcast Notes
    • Infrared light tends to penetrate more deeply into tissue and enhance mitochondrial activity as well as ATP + nitric oxide production
    • The Joovv emits both red and infrared wavelengths of light
  • The power density/intensity of something like the Joovv is is measured in mW/cm^2
    • That of the Joovv = 100 mW/cm^2 (this is much higher than random devices on Amazon)
  • So…
    • “Typically with a red light therapy device that has a power of ~100 mW/cm^2, you can get all the benefits you need in about 5-15 minutes if you are 2-6 inches away from the device”
      • There’s 0 evidence that a Joovv can cause harm by putting it right on the skin (just don’t leave it there longer than ~5-10 minute)
    • The closer a Joovv is to your skin, the less amount of time you need to use it for
  • But realize, more is not always better when it comes to red/infrared light therapy
    • Infrared light dissociates nitric oxide from a part of the electron transport chain called cytochrome C oxidase – if you do this too much you can create excess oxidation and free radical production
  • Ben’s protocol:
    • He owns 2 Joovv Elites and every morning sandwiches himself between them for ~10 minutes

Additional Notes

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