15 votes
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What animal has fat with the highest energy density?

In both humans and animals, the body fat stores appear as triglycerides, which can be composed of different fatty acids, but they all have about 9 kilocalories per gram (USDA). There can be different ...
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14 votes
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Can the human body create glucose out of fat?

Only about 5–6% of triglyceride (fat) can be converted to glucose in humans. This is because triglyceride is made up of one 3-carbon glycerol molecule and three 16- or 18-carbon fatty acids. The ...
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9 votes
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How can grass-fed livestock generate fat?

Short answer Plants typically store energy in the form of starch. Animals, including livestock and humans for that matter, can digest starch, metabolize it into acetyl-CoA and turn it into fat. ...
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9 votes
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Is palmitic acid really that dangerous?

Let's first clarify some concepts. Free fatty acids, including palmitic acid, are not present in animal tissues (or in the diet) to any large extent; they are esterified with glycerol to from ...
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  • 5,595
9 votes

How does body fat leave your body?

Many of the statements in your question are false, including your ideas about waste products. Ultimately, fats, just like carbohydrates, end up as water and carbon dioxide if they are used in ...
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8 votes
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Why are fatty acids consisting of even number of carbons predominant?

In short, it's because fatty acids are made from two-carbon blocks. The way that most organisms make fatty acids is by the successive addition of two-carbon units (acetyl-CoA). So we usually get ...
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8 votes
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Does LSD "stay" in your fat storage and then "returns" back?

I've heard this rumor for years, both from pro- and anti-drug people, and it is not true. According to this review of LSD's pharmacology, its half-life in the body is about 5 hours, with it being ...
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7 votes
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When you lose weight, how does the mass exit your body?

as CO2 and water in respiration sugar (or fat) is combined with oxygen to produce energy(ATP and heat), water, and CO2. fats are converted to Acetyl Co-A just like glucose is, the rest of the ...
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7 votes
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How does the human body extract energy from ethanol?

Preamble The question suggests unfamiliarity with the nature of biochemical oxidations and their relation to energy transfer in biology. The naïve reader is recommended to consult a text for a ...
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6 votes
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Bodyweight loss vs calorie shortfall

You hit upon several ideas in your post. First, you are absolutely correct that body fat is composed both of lipids and water, so a 10kg weight loss does not correspond to 90,000 kcals. The most ...
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  • 492
6 votes
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If eating 100% fat 2 times more worth the energy I spend during the day, will I store body fat?

There are a couple of reasons why this approach doesn't work quite as well as you might hope. First, insulin doesn't go away after a high-fat meal. This paper reports changes in serum insulin ...
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  • 710
6 votes
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Why is glycerol kinase absent from adipocytes but present in the liver?

The short answer to this question is given in the Wikipedia article on glycerol kinase: Adipocytes lack glycerol kinase so they cannot metabolize the glycerol produced during triacyl glycerol ...
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6 votes
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Breathing faster to lose (more) weight?

The rate of CO2 production is normally set by the rate of metabolism and breathing rate is determined by the level of CO2 in the blood. What you are suggesting is known as hyperventilation. Because ...
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6 votes
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Why are fatty acids synthesized in two carbon units?

The answer to this question lies in the chemistry of fatty acid synthesis — specifically the chemical energetics of the reactions. For those new to the biochemistry there is a basic concept that must ...
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5 votes
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Can lactate be created in ketosis?

First, there are inaccuracies and misconceptions in the article you quote, which also relates to obese people with insulin-resistance (pre type II diabetics) rather than normal people. These are: I’m ...
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5 votes
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Why does open olive oil keep so long?

Bacteria and other Microorganisms are mostly water, and to replicate they will need more water. The water they need is not present in olive oil. Salts and other required elements are also not present ...
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  • 3,150
4 votes

What are the benefits of statins in terms of prolonging life?

I suspect I won't be crunching as much numbers as you'd want me to, however here are some basic points: Statins have shown a clear ability to improve the blood llipid profile. Their use in primary/...
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4 votes
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naturally occuring fatty acids

The diversity of fatty acids produced by an organism is limited by the diversity of enzymes which synthesize them. Unsaturated fatty acids contain carbon-carbon double bonds which do not isomerize. ...
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4 votes
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Burning fat transferred from one part of the body to another

Would the body use this transferred fat for as energy, or would it ignore it as it wasn't stored there in the first place? It would use it as energy source, there is no such thing as "ignored ...
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  • 4,450
4 votes

Is there an evolutionary advantage for coconut oils to be rich in saturated fats?

This is entirely speculation, but the part of seeds that is pressed for oil(the endocarp) is enriched in saturated fats and long fats in ocean-going fruits. The coconut is 91% saturated fats, the oil ...
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4 votes
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Can bacteria metabolize fatty acids for fuel?

I found this review about bacterial lipid metabolism. There it says: Exogenous long chain fatty acids are utilized by E. coli in two ways. Firstly, they can be incorporated into the membrane ...
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  • 1,199
4 votes

What would happen if most the fat in your body was rapidly converted into energy in 2 minutes?

It depends, but you're going to die. Specifically, it depends on how fat you are. Even Andreas Munzer is going to die. At only 3% body fat, burning all his fat (9kcal/g) would "only" increase his ...
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  • 3,978
4 votes

Is the amount of cholesterol the body produces affected by how much cholesterol you take in with food?

Here's a study in which they measured a decrease in endogenous cholesterol synthesis after various amounts of dietary cholesterol: Dietary Cholesterol Feeding Suppresses Human Cholesterol Synthesis ...
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  • 7,949
4 votes

Why do humans lose subcutaneous fat tissue with age?

Short answer We do not loose fat (cells) as we age; on the contrary - we tend to gain fat by about 1 or 2% per decade. The place where it gets stored does change; instead of going into subcutaneous ...
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4 votes

Where does weight go when you lose it?

You breath it out, for the most part. Fat is "burned" to convert the carbons to CO2, which is breathed out. There's not very much fat-derived carbon in each breath, but you breath a lot, all ...
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4 votes

Why does the liver produce ketone bodies instead of exporting acetyl-CoA from beta-oxidation for use elsewhere?

This is simplified version of a complex situation, but in summary: A key role of liver is to control the distribution of metabolic fuel for the other tissues (it always has enough for its own ...
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4 votes
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Why is glycerol the backbone of fat?

Chance should always be high on our list of explanations of why the history of life turned out in some specific way. As James A. Coffman has described, there are a couple of different notions of ...
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4 votes
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Can fats clog veins or capillaries?

I know that so much fats running in the bloodstream could deposit in arteries, harden forming a plaque and cause atherosclerosis. But what about veins (which are formed from same types of layers as ...
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3 votes

Can the human body create glucose out of fat?

To be more detailed it is the irreversibly of the reaction carried by Pyruvate dehydrogenase that makes the conversion of the fatty acid chains to glucose impossible. The fatty acids chains are ...
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3 votes

What are the differences between carnitine forms?

Carnitine tartrate is a salt between carnitine (cation) and tartrate (the conjugate base of tartaric acid, anion). So in this case, tartaric acid is not covalently bound to carnitine. The salt ...
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