Thursday, March 24, 2016

Calories Are Not Created Equal

The next five blog posts will be dedicated to my individual topic discussing full-fat dairy versus low-fat dairy. I will evaluate the evidence in my next four posts and then draw a conclusion in my final post based on what I have presented. My last post will also include an infographic summarizing all the information I have found. For today, I would like to start off my argument of full-fat versus low-fat by discussing why calories are not created equal.



Many people still believe that a calorie in = a calorie out. The theory is that if you consume 2,000 calories a day, and your resting metabolic rate (how many calories you burn from just sitting or going about your normal daily activities) is only 1,600 calories, you are in an energy surplus of 400 calories. Over time, this surplus will cause you to gain weight. While I don’t entirely disregard the idea of our society consuming too many calories, I do not agree with this theory because it fails to take quality into consideration. The theory doesn’t ever discuss the type of food eaten and the impact on health. Technically, an individual who only consumes 2,000 calories a day of say two fast-food meals and regular coke is going to gain the same amount of weight as a person who consumes a 2,000 calorie meal of plain greek yogurt, homemade oatmeal, fresh fruit, a salad with vegetables and quinoa, and a dinner consisting of wild salmon, fresh vegetables, baked sweet potatoes, and cooked brown rice topped with grass-fed butter. But even though the second diet contains the same amount of calories, the two are clearly different! The healthy diet includes plenty of fiber, a well-rounded macronutrient distribution, and nutrients and vegetables which will promote fullness. Further, this meal is much healthier in terms of long-term health and the development of cardiovascular disease, type 2 diabetes, and even cancer.

Let’s break down another way to think about is this. Eating ~1,000 calories of fast food is not very hard and won’t leave you full long-term because of the lack of fiber. 1,000 calories of fast food would equate to eating 1 big mac and drinking one 32-ounce regular coke. But eating ~1,000 calories of broccoli would equate to eating over 30 cups of chopped broccoli!


Let’s compare the nutritional differences between the fast-food meal shown above and just eating broccoli.

A 1000 Calorie Comparison

Nutritional Composition Nutritional Composition
of Fast-Food Meal of Broccoli (30 cups)
Total Calories
903
930
Total fat
33.2
9 g
Saturated fat
8
0 g
Total Carbohydrate
130 g
180 g
Dietary Fiber
3.5 g
72 g
Sugar
91 g
45 g
Protein
26.6 g
78 g
Vitamin A
8%
330%
Calcium
26%
120%
Vitamin C
1%
4,050%
Iron
28%
90%
Vitamin B-6
0%
300%
Magnesium
11%
120%

Let’s first talk about fiber. The recommendation for fiber intake is 25 grams per day for women and 38 grams per day for men. The fast-food meal doesn't come anywhere near this, while the broccoli intake nearly triples the recommendation for women and doubles the recommendation for men. Even eating just two cups of chopped broccoli equals 5 grams of fiber and would outperform the fast-food meal. 30 cups contains 72 grams of fiber compared to 3.5 grams in the fast-food meal!

Obviously it would be very hard to consume 30 cups of broccoli because of lack of variety in taste, but also the high amount of dietary fiber! This high fiber content fills us up really fast and would take up a huge volume in our stomachs. This is another reason why whole foods are healthier. If we eat a meal full of healthy fat sources, vegetables, and complex carbohydrates, it will leave us fuller for much longer compared to the regular coke consumed in the fast-food meal. The regular coke is a liquid with no dietary fiber that goes straight through our stomachs and doesn’t fill up very much volume at all. Further, the lack of fiber means that the sugar in the coke will hit our bloodstream extremely fast, raising blood glucose and insulin levels. This fast sugar-spike and then consequent dip that will be created once our insulin comes in, will result in a blood sugar drop that makes us hungry again. When we consume foods with fiber and/or fat, it slows down digestion and the rate of increasing blood sugar, keeping us full for longer.

  

The graphs above show the glycemic index between coca-cola and broccoli. The glycemic index uses white bread as a reference to measure the impact of carbohydrate-containing foods on our blood sugar. The closer the food is to 100, the worse of an effect it has on elevating blood sugar quickly. Glycemic load is a more specific reference taking the amount of carbohydrate consumed as well as its glycemic index into account for the impact on blood sugar. As we can see, even drinking just 12 ounces of coca-cola has huge ramifications for the glycemic load and affect on blood sugar. As the amount of coke someone consumes increases, this glycemic load will go up even higher and have an even worse effect on blood sugar levels, which is bad news for our hunger levels and our insulin receptors. When we continue to consume too much sugar over and over again our insulin receptors become less sensitive or “resistant” to signals in our body and this is what increases risk for type 2 diabetes as well as other diseases.

Since we’re already on the topic of fiber and carbohydrates, let’s talk more about the sugar content in my example meals. You may be looking at the broccoli and thinking “Wow. 45 grams is still a lot of sugar.” But it is not added sugar. Added sugar is the big problem in our society. Added sugar is in the coke in the fast food meal as well as the white bread hamburger bun of the big mac. Added sugar intake from sugar-sweetened beverages such as the coke in this meal has been causally or directly linked to obesity and type 2 diabetes. The recommendation for added sugar intake is 150 calories per day for men, or 37.5 grams, and 100 calories per day for women, or 25 grams. The fast-food meal well exceeds this at 91 grams, and this is just one meal! According to data from the US in 2008, Americans are consuming an average of 76.7 grams of added sugar per day, which equals 19 teaspoons or 306 calories!

What does this have to do with fat and dairy? I will get into the specifics in my future blog posts but the problem comes back to the quantity vs. quality argument. A low-fat yogurt contains less calories than the full-fat product, but will leave you feeling less satiated. Not all fat is bad and it is important for many bodily processes which I will discuss in my next posts. Fat-free products usually do not taste as good to our receptors, so how do companies resolve this issue? They add sugar (or other fillers that are not healthy such as flour, salt, and thickeners). If the low-fat or fat-free version isn't as appealing to our taste-buds, we also might tend to eat more, which then defeats the purpose of eating the lower calorie option to begin.

I hypothesize that the added sugar is the problem today in our food supply, not the fat content, and that eating full-fat dairy, especially from good sources, will not increase our risk for chronic diseases as it’s been previously assumed. Even though the full-fat products contain more calories, calories are not created equal, and the source of the calories in terms of the food item and the specific macronutrient (whether the calorie is coming from fat or carbohydrate sources) makes a difference in our body composition and health.

Although this has only been an introduction, I hope to present the evidence for both sides of the fat argument in my next few posts, and will consider evidence for low-fat versus high-fat diet on inflammation, chronic diseases, and weight loss. In my next blog post, I will focus on why low-fat diets are not better than high-fat diets for many health outcomes. Hope you enjoyed, until next time!

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