My Take on Low-Carb Diets for Fat Loss

My progress pic: Evolutionary Nutrition + low carb

While the effects of low-carb dieting on health can be impressive as well, especially for people with metabolic derangement (insulin/leptin resistance), I want to stick to low-carb for fat loss at the moment. Just to be clear, an evolutionary or paleo diet is not by nature always a low carb diet, though it can be. 

Why are low-carb diets so effective for fat burning?

Without going in to the underlying hormonal causes, the real advantage of low-carb diets is the resetting of satiation signaling pathways. 

What I mean by this is that when you eat a diet low in carbohydrates, your bodies ability to send the signals to your brain that you are full, is greatly increased.

The end result of this is that people will feel full on less food.

In fact, several clinical studies show that subjects eating a low-carb diet until they are full often eat less than people on high-carb diets that are actively restricting calories.

This makes it relatively easy to lose fat when compared to a high-carb diet, because you simply aren't as hungry. 

However, it's important to remember that even if you are eating low carb, if you constantly eat past the point of feeling full, it is still possible to gain body fat. 

The other thing I want to emphasize about low-carb diets is that the majority of the health benefits that people see from them are likely because of the things they are not eating; the grains, legumes, sugars, etc. You will get a lot of the same effects of a low-carb diet by replacing these foods with safe starches.

Weight loss on a high-carb diet is possible, although I wouldn't recommend for most people. It usually leads to feelings of constant hunger, deprivation, and possible malnutrition due to a decrease in consumption of the most nutrient dense foods (meat, eggs, animal fat), which can results in fat-soluble vitamin deficiencies.

I will examine the underlying hormonal and metabolic effects of low-carb diets, and their relationship with longevity sometime soon.

Preventing Fatty Liver

Fatty Liver II.

A couple weeks ago I wrote a little bit about how children as young as five years old are getting Non-alcoholic Fatty Liver Disease (NAFLD) and discussed how fructose appears to be a causative factor (not the only one). It's kind of an important issue considering that as many as 100 million Americans probably have some stage of fatty liver disease.

Chris Masterjohn just published an article on his blog, The Daily Lipid, looking in to the research on what actually causes fatty liver. It's a bit technical, but the information is simply fantastic. In fact, Chris' work in general is some of the best there is on nutrition and health, and I highly recommend his blog. Anyway, I suggest you read his full analysis here, but I'll give a quick summary of his findings. 

Sugar, fat, alcohol and choline. 

In his review of the literature the evidence shows that alcohol, fat, and sugar/fructose intake ALL contribute to fatty liver, but only in the presence of a choline deficiency. It appears that a deficiency of choline impairs the ability of the liver to export the fat it creates from alcohol, fat, or sugar, effectively trapping it in the liver and leading to fatty liver disease. Adequate choline intake prevents this pathogenesis, even in the presence of sugar, fat, or alcohol. Chris wraps it up nicely here:

I have to conclude from all these studies that choline deficiency plays a role in virtually every type of diet-induced fatty liver model. The fat has to be provided to the liver through either dietary fat or dietary lipogenic substrates like ethanol and fructose, and the fat has to be trapped by impaired export of fats from the liver. And choline deficiency seems to be the preeminent cause of this.

Take home points.

• Fatty liver needs a choline deficiency to develop.
  
• Make sure you are getting adequate amounts of choline in your diet, especially if you are consuming large amounts of alcohol, fat, or sugar.
  
• The best food sources of choline are... Egg yolks and liver! Yum!

Any thoughts?

Non-alcoholic Fatty Liver Disease in Kids

A disturbing conversation

While I was in the University Health Center for some routine blood work yesterday, I learned something interesting.

The doctor I talked with happened to be a national speaker on diabetes, which lead us in to a conversation on the nutritional treatment of diabetes. She mentioned how having her patients stop drinking sugar (soda, juice, sweet teas), had remarkably improved health with just this one change. I agreed, chiming in that the massive amounts of fructose and sugar must me wreaking havoc on their livers, as the liver is the only site where fructose can be processed. The next thing she told me blew my mind:

Many of the children she sees as early as 5 years old are developing non-alcoholic fatty liver disease (NAFLD). Either we have some seriously negligent parents who are letting their kids start swigging vodka right after they get off breast milk, or little kids are eating way too much sugar!

NAFLD

Non-alcoholic fatty liver disease occurs when the liver is overloaded with more sugar than it can process. When this happens, the process of de novo lipogenesis starts - the conversion of carbohydrates in to "new fat", also known as triglycerides. As you may be aware, elevated triglycerides are not a good sign, and when this chronically happens at the liver, it can lead to hepatic cirrhosis (scarring of the liver).

The liver is a pretty important organ, if you know someone who's consuming tons of sugar, let them know that they are damaging it! The fact that we are seeing this in children as young as five is outrageous, as this condition is usually only seen in
diabetics or chronic alcoholics.

Recent studies

Research in the last 2 years (2,3) is showing that NAFLD is associated with increased mortality. A February 2010 Science Daily article reported on the new study that,

"findings suggest that for this study population, persistently elevated serum levels of liver enzymes was associated with an increased risk of death during the 28-year study period. Patients with NAFLD and NASH had a much higher risk of death than the general population but not as high a risk as for patients with chronic viral hepatitis or alcoholic liver disease."(1)

Apparently these findings are confirming what we already suspected: messing up your liver messes up your life. Decreased survival is not a good outcome...

Summary

Cut the soda, fruit juice, candy, and sugar out of your diet to live longer.

Update 11/23 : Preventing Fatty Liver

Sources:

1. Wiley-Blackwell (2010, February 1). Non-alcoholic fatty liver disease associated with high mortality rates. ScienceDaily. Retrieved October 2, 2010, from http://www.sciencedaily.com/releases/2010/01/100127095924.htm

2. Paul Angulo. Long-term mortality in NAFLD. Is liver histology of any prognostic significance? Hepatology, 2010; NA DOI: 10.1002/hep.23521

3. Cecilia Söderberg, Per Stål, Johan Askling, Hans Glaumann, Greger Lindberg, Joel Marmur, and Rolf Hultcrantz. Decreased survival of subjects with elevated liver function tests during a 28-year follow-up.Hepatology, 2009; n/a DOI: 10.1002/hep.23314