Is rapid fat loss possible with very low fat/very high carb diet?

The biology says YES.

As long as it’s a nutrient dense whole foods diet that you are consuming, it’ll make it that much easier. (keeps you from being hungry. There’s hormones at play here too. A lot more going on than meets the eye)

But, here’s the kicker. Dietary fat MUST be extremely low, or ZERO.

Pancreatic beta cells require fat to produce the insulin necessary to regulate blood glucose. Loading up on glucose, with no or very little fat, and the fat to produce the insulin necessary to deal with the glucose is forced out of your fat cells.

Now you can do this the conventional wisdom way, and basically feel like you’re starving all the time, or you can do it the Paleo way, and avoid those feelings all together.

Check out the very detailed post at Hyperlipid. Tough to understand, but I got the gyst of it. If you feel like getting into the nitty-gritty details, I suggest you read that post a few times. (That’s about how long it took me, hahaah)

So. Eat only potatoes and no fat for a while to get that 6-pack?

Potatoes have a very low glycemic load, meaning they slowly release a gentle stream of glucose throughout the day as they digest. They’re also loaded with just the right amino acid profile to spare muscle mass. There’s a ton of other good micronutrients in there too. I mean, you can basically live off of potatoes alone….

Maybe worth a try once spring comes around…. Meh, we’ll see if I can work my courage up to go all out on that one. HAH!

Are carbs required for fat burning?

Have you ever read or heard this phrase?

“Fat burns in the flame of carbohydrate”

It originates from a biochemist named Rosenfeld back in 1895. It was based on observations that cells could break down fatty acids into ketone bodies, but without sufficient glucose, the cells could not break them down fully into carbon dioxide and hydrogen.

We now know that fat actually burns in the flame of oxaloacetate.

Oxaloacetate can be derived from either glucose or amino acids. When we break down fats or carbohydrates for energy, we turn them into acetic acid, or acetate, which is a two-carbon unit.  A shuttle called coenzyme A, which is made of pantothenic acid, carries the acetate around and together we call the complex acetyl CoA.  Pantothenate is also called vitamin B5 and is found abundantly in many foods, particularly animal products.

In order to fully harvest energy from acetate, we need to send it through the citric acid cycle, also called the Krebs cycle or the tricarboxylic acid (TCA cycle).  This cycle will break the acetate down into carbon dioxide and hydrogen.  In doing so, it will also release high-energy electrons whose energy can then be harvested to synthesize ATP, a major usable energy currency of the cell.  Entry into this cycle is dependent on a compound called oxaloacetate.

 In the presence of glucose, we convert glucose to oxaloacetate.  As oxaloacetate leaves the Krebs cycle, we can just use glucose to replenish it.  In the absence of glucose, we do the opposite: we turn oxaloacetate into glucose.  Thus, oxaloacetate gets depleted in the absence of glucose, unless we have some other source of itWe can make oxaloacetate from a variety of amino acids, but not from fats.  Therefore, in the absence of dietary protein or carbohydrate, the only place to get oxaloacetate is to break down the lean proteins found in our muscles and internal organs.

As long as you’ve consumed sufficient protein, your body won’t break down your lean mass in order to make oxaloacetate.

Therefore, carbs are not necessary for fat metabolism.