34:07 – Time Restricted Feeding. There have been experiments done on mice where they were fed all sorts of foods and the effects on the expression of genes were recorded. One particular study took two groups of mice; one group was given a high fat diet and could eat whenever they’d like; the other group could eat the same sort (and same calorie count) of food but only eat in a designated window of time. There were sub tests of this test that looked at the size of the window: 8,9,10,11, and 12 hours.
37:20 – The benefits of time restricted feeding. The groups of mice that ate the same high fat diet but were limited to an eating window saw the following benefits:
- Mice Restricted to 12 hours:
- Decreases in fat mass in animals fed an obesogenic diet
- increases in lean muscle mass in mice fed a normal diet
- improvements in glucose tolerance and insulin sensitivity
- Reductions in inflammation. Improvements in lipid profile. Generally favorable changes in gene expression.
- Increases in mitochondrial volume, especially in the liver and brown fat, and an increased production of ketone bodies.
- protection from mild age-related hepatic steatosis (fatty liver). In the high-fat group this effect was especially robust: they experienced a 53% reduction in triglyceride accumulation.
- In mice restricted to 9 hours…
- An additional enhancement of endurance in the context of aerobic exercise.
39:13 – We don’t have much control over what and how much food we eat. We do however have a decent amount of control over our eating time. This can be a good entry point to a better living. All this research done points to time as being an important factor of nutrition.
40:20 – The mice experienced a 20% loss of body mass; 70% fat loss contributed most to this loss. Keep in mind these mice are eating the same poor diet but they are eating it when the liver can process it the best.
41:40 – Muscle mass. Mice given a normal diet gained more lean muscle mass when they restricted the intake of food based on time. It was a big surprise to see muscle mass increase after long periods of fasting; the mechanisms behind this are a bit of a mystery but there are correlates.
When researched wanted to know the answer to why muscle mass is increased, they focused on different compounds. One compound of interest was nicotinamide riboside (NR). NR is converted into NAD+ which is a coenzyme found in all living cells used to transfer chemical energy from a food source to the electron transport chain. NR is essential in the production of energy. Mice on a time restricted feeding cycle saw their levels of NR increase and this is one of Dr. Panda’s theories as to why we see an increase in muscle mass. We still cannot explain why there is muscle gain. [the mechanisms here are not explained very clearly. Questions such as ‘what is the relationship between these compounds and muscle mass?’ remain unanswered]
44:47 – Endurance. Mice who were restricted for 9 hours were recorded to have increased quantities of mitochondria and endoplasmic reticulum in the liver. Researchers also note that there is less damaged mitochondria in the tissue. This effect is not limited to the liver; there is increase mitochondria volume in brown adipose tissue (BAT). This is linked to an increase is PSG-1 Alpha – which is also observed. PSG-1 Alpha is the master regulator of mitochondrial biogenesis. PSG-1 alpha is also activated through cold stress such as cold-water immersion.