By a mom who happens to be a doc with an entrepreneurial spirit

The skinny on Fats and Carbs : that high fat low carb life

The skinny on Fats and Carbs : that high fat low carb life

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This month I decided to give keto a full-hearted effort. Why? I have been reading more and more about its potential benefits. Also, I know many people have amazing health results, form weight loss to improvements in their type II diabetes. So, I had to give the high fat low carb life a try. 

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My goal is not to lose weight. More than anything I want to experience ease of use and overall feeling while on it. However, after doing it for 2 weeks I have lost 3 pounds. I actually adjusted my plan to increase my intake of calories because I really don’t want to lose weight. By the way, I am using the carb manager app which has been great in tracking all my macros as I attempt the high fat low carb life.

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I personally tend to eat paleo, so this was definitely a change for me. I am decreasing my protein intake and boosting up my fat intake. Also, to be honest, intuitively it goes against every science and nutrition guideline I have had hammered into my head. Eating fat? That can be healthy? What? 

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We previously talked about the keto diet in this post. Check it out if you want to learn more.  Today, I would like to talk about the latest evidence exploring high fat and/or low-carb diets.

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Examining the evidence

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Before we begin, I would like to point out something important. Something we often overlook when we are exploring scientific research: correlation doesn’t mean causation.

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For example, an old study had suggested that coffee drinkers had a higher incidence of lung cancer. Therefore, it must mean that coffee causes lung cancers, right? Wrong. It turns out that, when they looked closely, a lot of the coffee drinkers were also smokers. As they studied smoking independently, they realized this was the link to cancer and not coffee. Suffice it to say, that just because two things seem to be associated, there may be more to the story. It is really hard to state, definitely, that one causes the other. So, often you will see words like “associated”, “linked” or “related”. This means that there seems to be something in common between them, but it doesn’t mean that one leads to the other. 

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Low-carb diets and weight loss

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Multiple systematic reviews suggest that low-carb diets lead to weight loss, possibly even more effectively than other types of diet. There are different levels of carbohydrate restriction, for all the flavors of high fat low carb life. The strictest one being the Keto Diet, which limits carbs to 20-50 grams/day. Although you are limiting your carbs, you aren’t really restricting your calories. Also, usually low-carb diets are high in fat and/or protein, depending on the type of low carb diet you are practicing. Most people state feeling fuller longer and don’t suffer the hunger that can accompany other diets. 

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Low carb, longevity and heart health

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There are many conflicting reports when it comes to this topic. It is certainly controversial. However, over the last few years, more evidence is coming out in favor for a low-carb lifestyle. One large study that came out in 2017 is the PURE study. I want to spend the rest of the time talking about this study. It is the largest one I could find, to date, looking at these issues. 

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What is PURE?

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The Prospective Urban Rural Epidemiology (PURE) study is a large, epidemiological cohort study of people between 35–70 years of age. They performed the study in 18 countries, with a median follow-up of 7.4 years. The investigators collected dietary intake of 135,335 individuals using validated food frequency questionnaires.

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Given the number of participants and the length of time they were followed, this gives us a lot of useful information. They specifically looked at mortality and heart disease risk, paying attention to the amount of fats, types of fats and carbohydrates that participants were ingesting.  

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It is important to note that current US dietary guidelines recommend eating a low-fat diet (<30% of energy) and limiting saturated fatty acids to less than 10% of energy intake by replacing them with unsaturated fatty acids. 

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Where does this fat recommendation come from?

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Well, it isn’t the most broad or thoroughly studied recommendation.

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The recommendation is based on findings from some North American and European countries where people have “food surplus”. Therefore, we can’t really generalize this information to countries that suffer from undernutrition. 

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In addition, North American and European populations consume a lower carbohydrate diet than populations elsewhere. Most people consume very high carbohydrate diets, mainly from refined sources because it is most often cheaper. These “over nourished” countries had both, high heart disease mortality and saturated fats intake. They noticed that in these countries, heart disease deaths decreased significantly when unsaturated fat replaced saturated fat. 

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These fat recommendations were based on:

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The assumption that the more saturated fat you eat, the higher your LDL (bad) cholesterol will be and the higher your risk for heart disease

Lack of consideration of blood pressure, which also affects heart disease, into the equation

Lack of consideration of the effect of saturated fats on HDL (good) cholesterol or apolipoproteins 

Apolipoproteins (Apo) are special proteins in our blood that bind fats and are believed to be better markers for heart disease risk. ApoB-to-ApoA1 ratio is the strongest lipid (fat) predictor of myocardial infarction (heart attacks) and ischemic strokes

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However, more recently, several clinical trials failed to show an association between saturated fat intake and increased mortality or heart disease. However, these were done mostly in developed countries, where saturated fat intake relatively low as dictated by dietary guidelines.

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Then came the PURE study, which looked at a mix of countries, some with problems of over nourishment and some with under. This study gives us the most rounded picture on fats and carbs yet. They included people from five different continents and of all socio-economic backgrounds. 

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What did we learn from the PURE results?

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TONS of interesting facts (IMHO).

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Some were as expected, the number one cause of mortality in all regions for non-heart disease causes (except Africa, where infectious disease was #1) was cancer.  

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When we look at food intake, China, south Asia and Africa had carb heavy diets. Fat heavy diets were more prominent in North America and Europe, Middle East, and southeast Asia. 

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In an effort to prevent data overload, here are the three most interesting points:

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*Higher fat intake was associated with lower risk of overall mortality, non-heart disease mortality, and stroke without any evidence of an increase in major cardiovascular (heart) disease, myocardial infarction (heart attacks), and cardiovascular disease deaths

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*High carbohydrate intake (more than about 60% of energy) was associated with an adverse impact on overall mortality and non-heart disease related mortality

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*A lower risk of stroke was observed when carbohydrate was replaced with saturated fatty acids, which is consistent with previous work showing that refined carbohydrate (such as white bread, white rice, sugar) intake is associated with increased risk of stroke

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So then is high fat low carb life the way?

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Should we jump on the high fat low carb life train? I think the study, at the very least, made a very compelling case for fats, including saturated fats, and against carbs. I am giving it a try. Of course, no study is ever perfect and we must always realize that there may be confounding factors. For example, is it possible that the people with higher socio-economic status are able to buy higher quality foods than those of lower socio economic status and would this possibly skew the data? Naturally, that is a possibility. Although the authors state they try to account for this.

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Nonetheless, this a huge study and hopefully as we continue to examine our dietary ways, we will continue to learn and evolve our practices. I will be keeping a close 👁 and, in the meantime, see how I do with my high fat low carb life trial.

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See you next time,

high fat low carb life


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