Nutrient density of dietary fats and high fat diets

 I decided to do a comparison of the nutrients in 500 kcalorie portions of olive oil, butter, lard, white rice, brown rice, potatoes, and sweet potatoes.   

I chose to include white and brown rice only because I wanted to find out if common animal fats really provide more nutritients, kcal for kcal, than white rice, commonly referred to as "filler" food.

I chose 500 kcalories because this would represent 25% of a 2000 kcal diet and 30% of a 1500kcal diet.  If you eat a high-fat, low-carbohydrate diet (more than 50% of kcals from fat), you will be getting most of your calories from fats.

Does this supply large amounts of fat-soluble vitamins or result in improved nutrient-density, compared, for example, to substituting white rice for those 500 kcal?  

I mean, does a diet that delivers 50% of its energy as fat really pack a nutritional punch, compared to one that delivers 50% of its energy as white rice, brown rice, potatoes, or sweet potatoes?

Using USDA data I compiled this table:

Click to Enlarge

Some observations:

1.  Sweet potatoes provide more vitamin E than any of the fats except olive oil, and potatoes supply almost 3 times as much vitamin E as lard and nearly as much as butter.

2.  None of the fats supply significant vitamin D; considering that our requirement is about 4000 IU daily, a 500 kcal dose of butter or lard provides only 1-1.4 percent of the daily requirement.

3. Butter delivers more micronutrients than either of the other fats, but the amounts are very small.  Except for vitamins A, D, and E, it doesn't even hold a candle to white rice.

4. A 500 kcal dose of butter provides only 50% of your vitamin A, and 11% of your vitamin E requirements. It provides no more than 2% of the requirement for any other nutrient.  By contrast, one teaspoon of cod liver oil provides 150%  of the vitamin A requirement, and 450 IU of vitamin D, ten times more than butter, and for only about 50 kcalories, one-tenth of the butter.

Kcalorie-for-kcalorie, enriched white rice meets more micronutrient needs than butter.  A diet providing 500 kcal as white rice, supplemented with a mere teaspoon of cod liver oil for your vitamin A, far surpasses the nutrient-density of a diet replacing those 500 kcal of white rice with either butter, lard, or olive oil, even if you include the teaspoon of cod liver oil. Choose brown rice, potatoes, or sweet potatoes and your vitamin and mineral intake will start to reach superior levels.  

Now, if you are trying to lose 25 to 50 pounds, you will need to be in energy deficit for 6 to 12 months.  If you consume 1800 kcalories daily, and 60% of those come from fats, which all have a very low vitamin and mineral density, you will need to get virtually all of your vitamins and minerals from the non-fat portion of your diet, which consists of only 720 kcalories. 

In Understanding Nutrition 6th Edition, Whitney and Rolfes point out on page 271 that "Nutritional adequacy is difficult to achieve on fewer than 1200 kcalories a day, and most healthy adults should not consume any less than that."  They make this statement in reference to a diet supplying only 20 percent of kcalories as fat.  A 60% fat, 1800 kcal diet is, from a nutrient-density perspective, equivalent to an 1100 kcal low-fat diet.  Most likely it will have multiple micronutrient deficiencies.

Now consider the following table, which lists the nutrients involved in metabolism of fats for energy as well as other functions. 

MICRONUTRIENTS INVOLVED IN FAT METABOLISM
Micronutrient	Role in fat metabolism
Thiamin	Part of TPP coenzyme in TCA.
Riboflavin	Base of coenzymes FMN and FAD required for TCA cycle and electron transport chain.
Niacin	Base of coenzymes NAD and NADP required for TCA cycle and electron transport chain; required cofacdtor for ∂-5 desaturase in EFA metabolism.
Biotin	Delivers carbon to the TCA cycle to replenish oxaloacetate; required for catabolism of some fatty acids and for fatty acid synthesis.
Pantothenic acid	Base for Coenzyme A (CoA) required for making acetyl CoA, which cells need for synthesizing lipids and steroid hormones as well as for running the TCA cycle.
Pyridoxine (B6)	Part of coenzymes PLP and PMP used in fatty acid metabolism and steroid hormone activity, cofactor for ∂-6 desaturase in EFA metabolism.
Cobalamin	Helps to break down some fatty acids.
Choline	Needed to synthesize the phospholipid lecithin.
VT-C	Required for hydroxylation of carnitine, a compound that transports long-chain fatty acids into the mitochondria for energy metabolism; cofactor for ∂-5 desaturase.
Tocopherols (VT-E)	Protect lipids from free-radical damage (esp. PUFAs)
Phosphorus	Part of ATP required in TCA cycle.
Magnesium	Catalyst in ATP formation; required for synthesis of lipids and elongation of essential fatty acids to produce prostaglandins.
Sulfur	Part of vitamins biotin and thiamin.
Iron	Part of hemoglobin required to deliver oxygen to cells for oxidation of macronutrients.
Zinc	Co-factor in EFA  metabolism.
Selenium	Part of glutathione, an assistant to VT-E.
Copper	Needed to make hemoglobin and in energy-releasing reactions.
Manganese	Cofactor in lipid metabolism.

If you develop a deficiency of any of the nutrients required for oxidation of fats to release energy, this may impair your ability to convert body fats to energy, and stall your loss of fat.

Notice that it is the B-complex vitamins, vitamin C, and minerals you need most to metabolize fats.  So far as I know, vitamins A and D play no role in fat metabolism, so the star vitamins in butter probably aren't going to help you burn body fat.

Thus, from a micronutrient standpoint, a diet providing 30% of its energy as free (i.e. refined) fats differs little from a diet providing 30% of its energy as refined sugar. 

If you have a higher energy requirement—say, 2500 kcal daily or more­­––this might not affect you.  You might get at least 1200 kcalories from meat and possibly vegetables, enough to at least meet minimum micronutrient requirements. 

This might explain why some people eating high-fat, low-carb diets feel and perform adequately over a longer term, while others do not.  I would expect that those on high kcalorie, high fat, low carb diets, more typically large, active men, would have a better micronutrient status and general health and results than those on low kcalorie, high-fat, low-carb diets, more typically small or sedentary women.

Since the nutrients in meat lie in the muscle or organ, not in the fat, high-fat meats have a lower micronutrient density than lean meats. Since requirements for B-complex vitamins vary in proportion to energy expenditure, if you have a high energy expenditure, it would seem rational to get your energy from foods with the higher density of B-complex vitamins, such as unrefined starches and lean meats, rather than surplus fats.

Regardless of energy requirement, I would rather choose the more nutrient-dense path, increasing my chances of superior micronutrient status without use of isolated supplements having questionable value and potential for harm.

Just a thought.