So is 30 to 35 percent total fat from calories a moderate-fat diet and above 35 percent a high-fat diet? How much fat, as a percentage of total calories, do you think is safe to consume?
What do you see as the safe upper limit for total fat intake?
How much saturated fat can one consume with out risking clogged arteries?
-- David Brown
Kalispell, MT
Since we are talking about ranges, there is room for fluidity.
Here is how I break it down.
Anything below 15 percent of total calories from fat falls under the “very low fat” category.
I classify the range between 15 and 30 percent of total calories from fat as "low-fat" (with, say, 16 percent being closer to “very low in fat” and 29 being very close to “moderate”).
The 30 – 40 range is "moderate", and anything above 40 is "high".
What makes your question much more complex, though, is that fat is by no means a simple nutrient.
I can not simply throw out a figure and say, “Consume 35 percent of calories from fat” without giving additional detail.
For example, make most of those fats mono and polyunsaturated, aim for an Omega-6 to Omega-3 ratio no higher than 5:1, and avoid artificial trans fats (some animal meats naturally contain trans fats, which I am not worried about).
If someone's “35 percent of total calories from fat” is mainly comprised of trans fats, I would certainly not describe it as healthy intake.
That same percentage consisting of mainly mono and polyunsaturated fats, however, would get two thumbs up.
This shouldn't come as a big shock to regular readers of this blog.
Besides, does anybody seriously think four strips of bacon or a quarter cup of half and half are healthier than a grilled wild salmon steak or half an avocado?
As for your safe upper limit question: you won't find a technical "Upper Limit" (how much of a nutrient it takes to have detrimental, rather than beneficial, health effects) for saturated fat.
However, the 10 percent figure (which, as I will explain a little later in more detail, basically recommends that people consume no more than 10 percent of total calories from saturated fat) serves as an Upper Limit.
Thereby, intakes of, say, 40 percent have not shown to be beneficial to health.
One main problem with mainstream talk about nutrition is that it oversimplifies nutrients, especially fats and carbohydrates.
After all, a carb is not a carb is not a carb. Oatmeal, bananas, and baked potatoes are very different from donuts and Jolly Ranchers.
The first three provide fiber, vitamins, minerals, and phytochemicals. The last two are virtually empty calories.
This is why I strongly oppose blanket statements like, "carbs are bad." Really?
You mean to tell me that fruits, vegetables, and whole grains are no different than a cupcake?
It is also important to place nutrients in the right context.
Sports nutritionists and exercise physiologists agree, based on evidence-based research, that easily digestible carbohydrates that would normally not be outright recommended as highly nutritious (ie: white rice) can serve an important purpose after a strenuous workout.
Forego carbs after a very intense, long workout and glycogen stores are not fully restored. This is problematic, as it may result in the breakdown of muscle.
As for how much saturated fat someone can consume without risking clogged arteries, you have to, once again, frame it in the appropriate context.
I stand by the “make no more than ten percent of your total calories saturated fat” rule, but keep in mind this is over a period of time.
Let’s assume you eat 2,500 calories a day.
Ten percent of 2500 calories = 250 calories.
Divide 250 calories by 9 (the amount of calories per gram of fat) and you get 27.7.
So, you should get no more than 28 grams of saturated fat a day.
Does this mean that downing 40 grams at a birthday dinner is going to send you into coronary hell? Not at all.
What matters, as I always like to mention, are general patterns.
If you generally stay within that 10 percent figure, your risk is lowered.
If, however, the norm is 30 percent (in this case, 83 grams of saturated fat a day) for five, ten, or fifteen years, you will very likely run into problems.
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5 comments:
Thanks for answering my questions, Andy. Pretty much everything you say makes sense.
I must confess that I've been consuming a high fat diet for at least 25 years. I did get into trouble back in 1995 likely because of my high intake of omega-6 oils. I was probably consuming too much mayonnaise and depleted myself of vitamin E.
The problem began in March when I bumped my shin on a saw horse. The wound scabbed over at first, than began to ooze pus and break loose. The cycle repeated itself over and over for weeks with the wound getting deeper each time it sloughed a scab. I visited both conventional and alternative medical practitioners and tried a number of remedies suggested by various friends and relatives. Finally, in June, I took a couple days off work and alternately soaked and elevated my leg. I had a book lying around the house entitled "Vitamin E Health Preserver" authored by Canadian Physician Wilfred Shute. Dr. Shute pioneered vitamin E treatments for various circulatory problems such as diabetic gangrene, congestive heart failure, phlebitis, and skin ulcers. I hadn't even considered vitamin E therapy because all my nutrition textbooks said that vitamin E "...is a nutrient in search of a disease." The authors all suggested that it is impossible to become vitamin E deficient. Well, I tried the vitamin both topically and internally and within two days I could sleep without aspirin and the wound began filling in with granulated tissue just as described by Dr. Shute.
I stopped consuming mayonnaise after reading about how toxic omega-6 vegetable oils can be. I've also done further research on saturated fats and cannot find evidence that even large quantities of saturated fats in natural configurations such as dairy, meat, coconut oil, palm kernel oils, and lard are harmful if adequate supportive nutrition is consumed in conjunction with the fat calories. That is, in order to properly utilize saturated fat calories, nutrients either stored in the body somewhere or included in the diet get used up and excreted. The same holds for other sources of pure calories such as sugars, starch, and alcohol.
I suggest you do some research on polyunsaturated fats. I personally see them as unsafe in amounts greater than would normally be found in whole foods. This whole seed oil business is relatively new to the dietary scene and deserves more scrutiny than it currently gets. Try this article: http://raypeat.com/articles/articles/unsaturated-oils.shtml
David,
I don't think it's fair to classify polyunsaturated fats as a whole as unsafe.
I say this because both Omega 6's AND Omega 3's are polyunsaturated.
The important thing when it comes to polyunsaturated fats is to keep the desired Omega 6:Omega 3 ratio in mind (no more than 5:1, ideally 4:1 or less).
When do you sleep?
It's the dose that determines toxicity. Also, it's important to consider what other sorts of nutrients are or are not being consumed on a regular basis. Finally, individual biochemistry determines how much polyunsaturated fat one can tolerate without apparent harm.
Someday I hope to see the nutrition debate shift from discussion of the beneficial effects of single nutrients to a more context orientated approach. For example, researchers studying vitamin A toxicity found that the toxic effects did not manifest themselves when adequate vitamin D was present in the system. Living organisms are complex chemical factories that require adequate amounts of all reactants to function at an optimum level of well-being.
Below is some comment by Dr. Raymond Peat. I don't agree with everything said here. And I don't know enough about biochemical research to argue against his assertion that the concept of essential fatty acids was disproved over 50 years ago. What I do know is that we Americans have been consuming enormous amounts of omega-6 fats for decades.
You can read the entire article at http://raypeat.com/articles/articles/unsaturated-oils.shtml
Q: You say vegetable oils are hazardous to your health. What vegetable oils are you talking about?
Mainly, I'm referring to soybean oil, corn oil, safflower oil, canola, sesame oil, sunflower seed oil, palm oil, and any others that are labeled as "unsaturated" or "polyunsaturated." Almond oil, which is used in many cosmetics, is very unsaturated.
Chemically, the material that makes these oils very toxic is the polyunsaturated fat itself. These unsaturated oils are found in very high concentrations in many seeds, and in the fats of animals that have eaten a diet containing them. The fresh oils, whether cold pressed or consumed as part of the living plant material, are intrinsically toxic, and it is not any special industrial treatment that makes them toxic. Since these oils occur in other parts of plants at lower concentration, and in the animals which eat the plants, it is impossible to eat a diet which lacks them, unless special foods are prepared in the laboratory.
These toxic oils are sometimes called the "essential fatty acids" or "vitamin F," but this concept of the oils as essential nutrients was clearly disproved over 50 years ago.
Linoleic and linolenic acids, the "essential fatty acids," and other polyunsaturated fatty acids, which are now fed to pigs to fatten them, in the form of corn and soy beans, cause the animals' fat to be chemically equivalent to vegetable oil. In the late 1940s, chemical toxins were used to suppress the thyroid function of pigs, to make them get fatter while consuming less food. When that was found to be carcinogenic, it was then found that corn and soy beans had the same antithyroid effect, causing the animals to be fattened at low cost. The animals' fat becomes chemically similar to the fats in their food, causing it to be equally toxic, and equally fattening.
These oils are derived from seeds, but their abundance in some meat has led to a lot of confusion about "animal fats." Many researchers still refer to lard as a "saturated fat," but this is simply incorrect when pigs are fed soybeans and corn.
I've always been a night owl (doesn't go so well with 7:30 AM wakeup calls, though!).
I have no idea where the statemnt of essential fatty acids being disproved comes from.
It is a well-known fact that our bodies do not produce all the EFA's we need.
In fact, I am not sure where Dr. Peat is getting his information from.
It is well-known that the beef made from cows fed corn and soy is higher in saturated fat (and lower in Omega 3's) than that of grass-fed cows.
So this idea that an animal's body fat imitates the fat they are being fed doesn't sound right.
You raise a good point about context-oriented approaches.
For instance, you'll see reports that antioxidant supplementation (say, vitamin E) does not affect a health issue (i.e.: cancer risk).
However, it is important to note that nutrients are not eaten in a vaccuum.
It is often the combination of them in a given food or meal (along with, say, the plant phenols in seeds and legumes that are not contained in a vitamin E pill) that are associated with health benefits.
This is what I was getting at with the nutrient-centric (and nutrient-obsessive) mainstream pop-culture nutrition (i.e.: talking about "fat" as one nutrient without discussing the sub-categories and details).
Thanks for your interest.
In the May 28, 2008 Willamette Week Murmurs column (http://wweek.com/columns/murmurs/#34.29) there's a story about A man doing 25 months in state prison for assault. He's suing Multnomah County and a Philadelphia-based food distributor for serving food he says led to a near-fatal heart fibrillation. He claims he was subjected to “criminal inhumanity” in 2007 at the county’s Inverness Jail, where he says food did not comply with the low-fat diet prescribed by his cardiologist. Do you think this lawsuit has any merit?
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