Good Fats and Bad Fats?

pennell12

Hi all,

I am new to LCHF and have a question. I know that a lot of the old low fat advice doctors and the medical establishment espoused has been debunked. However, how about the Saturated Fat/Trans Fat/Mono Saturated fat issues? Is Saturated fat still considered bad for the arteries?

Also, generally speaking, what is the recommended ratio of cars/fats/proteins on LCHF diet?

wabmester

Everybody seems to agree trans is bad.

Some people seem sensitive to SFA. If you see your LDL go way up, consider substituting MUFA for SFA.

The interesting ones seem to be the MCTs, including those found in butter and coconut oil. Your body doesn't store them, so they get prioritized for burning, and they can boost ketone levels in the process.

Ratios of macros don't matter as much as absolute values. Set your carbs low -- whatever level works for you. Set your protein to maintain muscle mass. Again, it varies, but around 1g per kg of body weight is a rough guide. And fat to fill out your calories until you reach satiety.

Frankly, after 6 months on LC, I reach satiety pretty easily, and I don't have to go out of my way to add fat like many people seem to. I contribute body fat instead.

sweetteadrinker2

You need some saturated fat, preferably mono-unsaturated, to repair your cell membranes. MCTS are an oddity, your body could in theory store them but it would very much rather just dump them, so they help increase ketones that way.

nvmomketo

Ditto everything @wabmaster said. I think trans fat is the only unhealthy one. It appears to be excess carbs that cause us to make our own saturated fat, and not dietary fat - at least that's what I have read.

Ratios vary. Protein seems to be between 20 and 30% for most. I think carbs are often 20% or less, often closer to 5% for very low carb. Fat is often 60-75%. All very rough.

pennell12

Thanks! May I ask what these are: MCTs, MUFA? Its hard to switch over the SF after years of being told they are bad for us

wabmester

MCT = medium-chain triglycerides. Basically, short- and medium-chain fats in the diet get absorbed directly into the blood, so they get handled differently that long-chain fats that need to be transported via LDL and friends.

MUFA = mono-unsaturated fatty acids.

As @nvsmomketo implied, SFA in the blood is potentially bad, but when carbs are high, we make our own, and when you're LCHF, you burn them at a higher rate, so you can actually end up with a lower serum level even with higher dietary intake.

That's one of the miracles of LCHF.

Dragonwolf

The way I look at fats is this:

Regardless of dietary fat intake, the human body stores excess fuel as fat in the following ratios:

30-50% Saturated (primarily palmetic acid)
40-50% Monounsaturated (primarily oleic acid, the primary fatty acid in olive oil)
5-15% Polyunsaturated (primarily linoleic acid)

What this means is that even if your diet was completely devoid of fat, if you're losing weight, your body is using fat in those ratios, and if you're gaining weight, your body will store it in those ratios. The exact numbers (and exact ratios of fatty acids) can change depending on diet, but these percentages stay within this range.

If saturated fat is so bad for us, then why does it compose nearly half of our body fat, regardless of diet?

The problem isn't saturated fat, but the lumping of saturated and trans fats in the studies. Trans fats are bad. Horrible, in fact. Seriously. Avoid them like the plague. Good fats don't need hydrogenation.

Naturally occurring saturated fats, though? Actually required by the body for proper function and hormone balance.

Here's another fun fact for you -- the difference between saturated fats (the supposed "bad guy") and monounsaturated fats (the supposed manna from heaven of fats) is a single hydrogen atom. Saturated fats have a single hydrogen atom bonded to every carbon atom. It's what makes them very heat and shelf stable. Monounsaturated fats have one double bond somewhere in their chain, meaning it's lacking a hydrogen atom, so two of the carbon atoms are bound to each other. Polyunsaturated fats have more of these double bonds, each additional double bond makes it less shelf and heat stable, which is the main problem with PUFAs. (The process of hydrogenation forces hydrogen into those double-bonds, saturating the fatty acid chains, but does so in a rather bastardized way, creating trans fats, hence the problem with trans fats.)

Check out the links the Launch Pad. There are a number the specifically address the horrid lack of scientific backing of the USDA guidelines for the past 60+ years.

Lunawatuna

Omega 3 good, but 6 not so good. Saturated fats ok trans fats and seed oils not. Best fats: Butter and cold pressed coconut oil for cooking; extra virgin unblinded olive oil for drizzling.

wabmester

Dragonwolf wrote: »

30-50% Saturated (primarily palmetic acid)

[...]

Naturally occurring saturated fats, though? Actually required by the body for proper function and hormone balance.

You realize that we make palmitic acid in response to carb intake, right? That's the output of DNL, and it's associated with all sorts of nastiness.

http://www.ncbi.nlm.nih.gov/pubmed/25527759

Like anything else, probably good in small quantities, but we weren't designed to make so much of the stuff.

Edit: Volek has proposed palmitoleic acid (a MUFA) as a better biomarker of DNL.
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0113605