A High FAcT Diet
There are 2 diets that are very popular now, and they are almost diametrically opposed. One is the resurgence of the ketogenic diet, which is high-fat, low-carbohydrate. The other is the whole food plant-based diet, which is generally low-fat and high-carbohydrate. Which one is better? Are there benefits to both? Can they be combined? Before we start answering these questions, let's go through a little bit of history. The low-fat diet was very popular in the 1980s and 1990s. The assumption was that a low-fat diet would reduce cholesterol, while carbohydrates were not viewed as contributing to obesity or heart disease in any way. Why most low-fat diets recommended by doctors consisted of complex carbohydrates and vegetables, many food manufacturers made low-fat or fat-free ice creams, among other things, replacing fat with sugar. The sugar industry, which funded research to support low-fat diets, certainly made money from this.
Now it should be no surprise that adding a lot of sugar would cause people to gain weight. However, what about the people on low-fat diets prescribed by doctors? Certainly cutting back on fats would help with reduce help with weight loss and also reduce the risk of heart disease? While this can be true depending on the type of fat, and certainly many people got healthier by cutting back on meat in diets like the Dean Ornish program, not all fats are the same. Some fats, such as mono-unsaturated fats in nuts and avocados as well as omega-3 fatty acids in flax seeds, are beneficial for the heart. They also help with weight loss moreso than carbohydrates as they are more filling. Many people did a 180, assuming that carbohydrates are the enemy while we can eat fat as much as we want, regardless of the type of fat. The Atkins diet rose out of the this low-carb craze. The Atkins is a variety of a ketogenic diet, which involves consuming such a small amount of carbohydrates that the body burns fat rather than sugar as its main fuel source. While in theory this make sense, the results of the Atkins diet have shown weight loss mostly consisting of water weight. Long-term studies have yet to be done, with studies often being no more than 2 years. https://www.mayoclinic.org/healthy-lifestyle/weight-loss/in-depth/atkins-diet/art-20048485
Side effects of such diets include
If the low-fat, high-carb diet caused weight gain while the high-fat, low-carb Atkins diet had such side effects, how does one lose weight and be in good health? Surely there are people who are losing weight and staying healthy? One problem with the Atkins diet is that it is high in SATURATED fat, which are more likely to clog the arteries. Also, because the fat is mostly from animal products, there is less fiber, which may help explain the diarrhea and constipation; and less water; which may explain the headaches, dizziness, weakness, fatigue, etc. Surprisingly, there is in fact a plant-based version of the Atkins diet, dubbed the "eco-Atkins." And it turns out to fair better than the regular Atkins diet in terms of effect on heart disease.
As we saw earlier, the low-fat craze failed, which is the whole reason why the Atkins diet grew. If it has been a failure, why is it that some people swear to it being better for weight loss? Why has it been successful for some people but not other? Let's take a look at one particular study in the American Journal of Clinical Nutrition. A study was done on patients with type 2 diabetes comparing a low-carb, high mono-unsaturated fat group and a high-carb, low-fat group. They were expecting the high fat group to lose more weight. But what happend? "Body weight decreased significantly (1.53 kg; P < 0.001) only with the low-fat diet. Plasma total, LDL-, and HDL-cholesterol concentrations tended to decrease during both diets. There were no interaction effects between diet and the lipid profile response over time. Plasma triacylglycerol concentrations, glycemic control, and insulin sensitivity did not differ significantly between the 2 diets." So it turns out that there was very little difference in lipid profile, and the low-carb group actually lost more weight. https://academic.oup.com/ajcn/article/80/3/668/4690545
Now the sample size was only 11 people (8 women and 3 men), so it should be taken with a grain of salt. However, any large study consists of many individuals, with each individual providing useful information. So although we should take it with a grain of salt (or drop of oil since we are talking about fat), we shouldn't ignore it but rather compare to other studies. What can be a reason for the low-fat diet to have more weight loss? Perhaps more fiber as high-fiber foods are more likely to be low-fat. Perhaps more water consumption, which has no Calories, as opposed to consuming more oil? Maybe the high mono-unsaturated fat group had lots of olive oil as opposed to whole olives and avocados, and thus they consumed too many Calories without fiber to fill them up and prevent them from over-eating? Let's see how they performed the study. "In general, high-fat items and oils on the high-mono diet were partially replaced on the low-fat diet with fat-free oils and foods higher in complex carbohydrates." And in a later paragraph, we have more details: The low-fat diet provided 20% of energy as fat, and the high-mono diet provided 40% of energy as fat (26% of energy was monounsaturated fat; Table 3). The low-fat diet provided 65% of energy as carbohydrates compared with 45% as carbohydrates for the high-mono diet; refined sugar made up 10% of energy intake in both diets. The low-fat diet was higher in fiber and water content, weighed more, and had a lower energy density (kcal/g diet) than did the high-mono diet." It may also be that the high mono unsaturated fat may also have more saturated fat. Maybe it was a Mediterranean diet and thus had olives but also feta cheese, lamb, etc. Or maybe something other than fat and carbohydrates played a role? Protein can be another factor. Maybe the high mono diet was higher in protein? Or what about animal protein vs plant protein? It is hard to say given the description. We do have other research that suggests animal protein is associated with higher all-cause mortality. While it may or may not have played a role in the diabetes group, it certain is a factor to look at for overall health. https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2540540
More fiber and fewer Calories can be an explanation for the greater weight loss on the low-fat diet in the diabetes study. According to some people, this may settle the issue...a low-fat, high-carbohydrate diet is clearly superior for weight loss and heart health. The low-fat diet of the 80s and 90s failed because you had a ton of people eating high-sugar ice cream. But a whole-food plant-based diet that is absent of refined carbohydrates is the way to go, according to the philosophy. WFPB can mean a lot of things. Generally it means whole grains, legumes, vegetables, and fruits. Certainly it can be a healthy diet. But is it the optimal diet? It is certainly healthier than the Atkins diet, but as it tends to be low-fat, it may also mean low in healthy fats. Also, potatoes and corn are considered WFPB by many. But would a diet with more potatoes and less avocado be optimal? Or would we be better off with more avocado, less potato. And heck, would we benefit from replacing some whole grains with avocados? Let's take a look at another study, this one with 80,000 subjects, all women. https://www.hsph.harvard.edu/nutritionsource/what-should-you-eat/protein/ While the article is mostly about protein, here is a sentence that stood out about fat and carbohydrates: "A 20-year prospective study of over 80,000 women found that those who ate low-carbohydrate diets that were high in vegetable sources of fat and protein had a 30 percent lower risk of heart disease compared with women who ate high-carbohydrate, low-fat diets. Diets were given low-carbohydrate scores based on their intake of fat, protein, and carbohydrates. (9) However, eating a low-carbohydrate diet high in animal fat or protein did not offer such protection." Given that high-fat plant foods such as avocados are also high in fiber, it may be that a more optimal diet is high in fat, but provided that the fats are mono-unsaturated, omega-3 fatty acids, or other healthy fats instead of saturated fats. I would like to emphasize the word "saturated" fat as some assume that it is mainly about plant foods vs animal foods. Many people are crazy about coconut oil, believe it to be a cure for many ailments and also lowering the risk of heart disease. Other say it is bad for the heart. It seems that the research is mixed, and this may be because coconut oil increases both LDL (bad cholesterol) and HDL (good cholesterol). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5745680/ So for somebody who has high LDL, it may not benefit to increase HDL while also increasing the LDL. However, for an athlete with low LDL, maybe a boost in LDL won't be so bad, and the boost in HDL may have some benefits. But as we are talking about optimal health, it may be better to get most fat from olives and other more heart-healthy fats. Now chocolate is high in saturated fat, but it appears to react differently from coconut oil. While chocolate is high in saturated fat, the type of saturated fat is stearic acid, which converts to heart-healthy monounsaturated fats. https://www.ynhh.org/services/nutrition/chocolate.aspx
Milk also has stearic acid, which is one reason why some people promote butter. However, milkfat is approximately 11%-12% stearic acid. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2596709/ About 30% of the fat in milk is palmitic acid, which tends to raise LDL.
While chocolate itself has heart-healthy fats, most chocolate products tend to have a lot of added sugar and dairy cream, which is high in harmful saturated fat. So try to get dark chocolate that doesn't have milk chocolate. Also, try to get stevia or monk fruit sweetened instead of sugar-sweetened. Or try to get semi-sweet that is low in sugar. One common reason for recommending coconut oil is because it has a high smoke point. In other words, healthy fats like those in olive oil break down when you heat them at certain temperatures, but not with coconut oil. It is true that coconut oil has a higher smoke point than olive oil and thus has less oxidation after cooking. http://grasasyaceites.revistas.csic.es/index.php/grasasyaceites/article/view/733/746
It is a good idea to use olive oil raw rather than heating it. While coconut oil experiences less damage from frying than olive oil, it still is high in saturated fats that raise LDL. Is there a way to get the benefits of olive oil but with a higher smoke index? It seems that avocado oil, which is high in mono-unsaturated fat, also has a high smoke point, and thus is a better alternative for cooking than coconut oil. https://link.springer.com/article/10.1007/BF02542367 It would seem the best diet should be ones consumed by the longest living people in the world. Until recently, the Okinwans were the longest living people in the world. There diet is high in vegetables, sweet potato, low in processed foods, etc. Some will argue that it is because of fish. Others will say it is because of low-fat. Maybe few others will say it is because they consume soy. Obviously it is a mixture of factors. Let's look at more details on their diet compared to the rest of Japan. "The dietary intake of Okinawans compared to other Japanese circa 1950 shows that Okinawans consumed: fewer total calories (1785 vs. 2068), less polyunsaturated fat (4.8% of calories vs. 8%), less rice (154g vs. 328g), significantly less wheat, barley and other grains (38g vs. 153g), less sugars (3g vs. 8g), more legumes (71g vs. 55g), significantly less fish (15g vs. 62g), significantly less meat and poultry (3g vs. 11g), less eggs (1g vs. 7g), less dairy (<1g vs. 8g), much more sweet potatoes (849g vs. 66g), less other potatoes (2g vs. 47g), less fruit (<1g vs. 44g), and no pickled vegetables (0g vs. 42g).  In short, the Okinawans circa 1950 ate sweet potatoes for 849 grams of the 1262 grams of food that they consumed, which constituted 69% of their total calories." http://okicent.org/?reqp=1&reqr=pzRhnaM4qzAlpKMhYzWyqN== So although their diet is high-carb in terms of percentage of Calories, and low-fat, they consume less total amount of carbohydrates. Also, most of their carbohydrates are from sweet potato rather than grains. They also consume less fish than the rest of Japan as well as less animal products in general. However, they also consume less fruit. They also consume more legumes. Much of their legumes are soy beans. It is hard to pinpoint exactly which factors are helpful and which are merely reduced amount. But it does seem that fewer Calories, less refined grains, and less meat played a role. There are many diets that are healthy. Some may benefit from a low-fat, high complex carbohydrate diet. Others may benefit from a high fat, low carbohydrate diet. Low fat diets tend to be healthier from many because of more water and fiber as well as less saturated fat and cholesterol. High fat diets improve health for some people because they may contain more omega-3 fatty acids and less sugar, starch, etc. It just may be the optimal results come from combining the two. So instead of lots of butter and steak, try lots of almonds and avocados. Now this doesn't mean we should give up grains and fruit, but cutting back on grains may be healthful for some.