The Nature of a Healthy Diet
Since carbohydrates make us fat, Taubes holds that "the best and perhaps only way to avoid becoming fat is to avoid the carbohydrate rich foods that are responsible" (173). However, many argue against going on carbohydrate restricted diets for three main reasons, three reasons that Taubes does his best to dispel.
The Con Job Argument
The first argument is that carbohydrate rich diets are scams because they promise weight loss without having to eat less and/or exercise, thus violate the laws of thermodynamics and the primacy of calories-in, calories-out (Taubes, 173). Taubes argues against this argument using the science of weight accumulation. He says that if we restrict carbohydrates, this will lead to weight loss because of the decrease in insulin secretion - which happens independently of the calories we consume from dietary fat and protein. Therefore, the laws of physics have nothing to do with it.
The Unbalanced Diet Argument
The second argument is that carbohydrate restricting diets are unbalanced, because they restrict an entire nutrient category - carbohydrates - and the first of healthy eating is to eat a balanced diet from all the major food groups (Taubes, 173). Taubes argues that his idea of restricting carbohydrates in order to live healthier is just like doctors telling smokers to restrict their cigarette use for their health. He says that doctors don't care if we find life less fulfilling without cigarettes, they want us to be healthy, and they assume we'll get over the absence given time - just like we will, as Taubes argues, with carbohydrates (174). If, however, we are to go on diets that cuts back on all calories equally, Taubes argues that we will still be eating more of these carbohydrate rich foods, and will not lose weight while hunger will be a constant companion (174).
When Taubes talks about restricting carbohydrates, however, he does not mean to cut them out completely. Rather, he just advises us to stay away from what he calls the "fattening carbohydrate". These cannot be found in the leafy green vegetables and salads, but are actually found in starches, refined carbohydrates, and sugars (175). Taubes tells us to restrict our intake of fatty carbohydrates but to eat as much meat as we like. While many doctors and nutritionists will tell you to cut back on your meat consumption because of its high percentage of calories that come from fat; they don't tell you that meat contains all the amino acids necessary for life, all the essential fats, and twelve out of the thirteen essential vitamins in surprisingly large quantities (Taubes, 176). One vitamin that is very scarce in meat, however, is vitamin C. Interestingly, while we work so hard to increase the amounts of vitamin C in our diets, the vitamin uses the same mechanism to get into our cells as glucose does. So while we can get vitamin C from a whole host of sources, much of it will be excreted in the urine rather than retaining it because its spots will be taken up by glucose (Taubes, 176).
In addition to it effects on vitamin retention, a lack of carbohydrates in the diet also effects the molecules the brain will use for fuel also changes - to ketones. Ketones are synthesized in the liver from the fat we eat and from fatty acids, from our fat tissue with low carbohydrate diets, and from amino acids (Taubes, 177). The rest of our brain's energy will come from glycerol, which comes from breaking down triglycerides in fat cells into glycerol and two fatty acids. Research has shown, actually, that the brain and central nervous system runs more efficiently on ketones than they do on glucose - therefore we only need about 60 grams or less of carbohydrates a day for our bodies to run correctly (Taubes, 178).
The Heart Disease Argument
The final argument is that carbohydrate restricting diets are high-fat diets, and particularly high in saturated fat, and will cause heart disease by raising our cholesterol (Taubes, 173). For years we have bought into the idea that if we lower these supposedly "heart-healthy" carbohydrates, and replace them with high fat foods and especially saturated fats, which raise our cholesterol and increase our risk of heart disease and premature death. However, the validity of this claim must be looked into. How is it that a diet that makes us leaner by lowering cholesterol and increasing fat intake can also cause us to have an increased risk for heart disease? This is what Taubes refers to as a paradox of our diets (179).
Nutritionists and health authorities "argue that fat is the most energy dense nutrient in the diet, and this makes it fattening" (Taubes, 180). A gram of fat has 9 calories compared to the 4 calories contained in a gram of both protein and carbohydrates. This fact has, and will be used to help argue towards avoiding high-fat, low-cholesterol diets in order to maintain weight loss. However, as Taubes tells us, "as a nation, we were told to eat less fat and less saturated fat, which we did, or at least tried to do and yet, rather than getting leaner, we got fatter." (181) Taubes also tells us that coincidentally, the emergence of the low-fat, high-carb diet came about at the same time as both the obesity and the diabetes epidemics (182).
In addition to these facts, Taubes reveals that there is actually very little experimental evidence in support of the idea of a low-fat, high-carb diet helping to lower the risk of heart disease. In fact, one experiment conducted by the NHLBI, where over $115 million dollars was spent to conduct a decade-long clinical trial of eating less saturated fat to curb heart disease, ended in complete failure (Taubes, 182). However, a second trial, costing over $150 million dollars, that studied the benefits of a low-cholesterol diet helping to lower risk of heart disease succeeded (Taubes, 182). While researcher could prove that lowering cholesterol helped to prevent heart disease, they still could not prove that either a low-fat diet or a low-saturated fat diet could do the same (Taubes, 183). Even one of the most highly respected organizations called the Cochrane Collaboration, which gives unbiased information on intervention techniques, said that "there is still only limited and inconclusive evidence of the effects of modification of total, saturated, monounsaturated, or polyunsaturated fats on cardiovascular morbidity and mortality." (Taubes, 184)
Finally, Taubes argues that we must take into account the cause and effects with taking cholesterol-lowering drugs. Taubes says that taking a drug to lower cholesterol and changing our diets to lower cholesterol do two completely different things. Changing the nutrient content of our diets can effect much more than just our levels of cholesterol. And we can't actually prove if lowering the cholesterol in our diets will effect our risk of heart disease. Taubes says that. "just because drugs known as statins lower LDL cholesterol and prevent heart disease does not necessarily imply that they prevent heart disease because they lower LDL." (186)
Many things can be markers for potential heart disease in humans. One thing is a high triglyceride count. The more triglycerides in our bodies, which come from eating carbohydrates, the greater the likelihood that we will obtain heart disease. LDL is a second marker. If your LDL is high, then you also have a greater chance of getting heart disease. Finally, low HDL (good cholesterol) is a risk factor for heart disease. HDL can become lowered when you replace the fats in the diet with carbohydrates. Many will tell us to increase our exercise, lower our weight, and consume alcohol in moderation; but even more than any of those three things, if you lower your carbohydrate intake and replace it with fats, then you will raise you HDL.
Foods in general do not contain just one type of fat, but rather a mixture of different fats that all affect LDL and HDL levels. Monounsaturated fats raise HDL and lower LDL. 1/3 of saturated fats contain stearic acid that is considered a "good fat" because it raises HDL, but has no effect on LDL. Finally, polyunsaturated fat lowers LDL but has no effect on HDL (Taubes, 189).
Over the years, many studies have emerged to research the effects of the low-carbohydrate diet, many ending up with the same results: loss of weight, rise in HDL, lower Triglycerides, lowered Blood Pressure, same Total Cholesterol, LDL slightly increased, significant Decrease in Risk for Heart Disease (Taubes, 190).
In one study in particular, the A to Z Weight Loss Study, a research team from Stanford University compared four different diets and their results; including the Atkins diet, a traditional diet (LEARN diet), the Ornish diet, and the Zone diet. They found that the diet that restricted carbohydrates (Atkins) actually resulted in more weight loss, lower triglycerides, higher HDL, and lower Blood Pressure than any other diet (Taubes, 191). When faced with these results, even the director of the study, a vegetarian himself for 25+ years, had to admit that the triumph of the very low carbohydrate, meat rich Atkins diet is "a bitter pill to swallow" (Taubes, 192).
The "Bad Cholesterol" Problem - Updating the LDL Connection
According to Taubes, when physicians and health reporters "began to refer to LDL as the "bad cholesterol", they did so because they thought it was the cholesterol that caused the buildup of plaque in our arteries. LDL, though, actually isn't cholesterol; it's the particle that contains the cholesterol and shuttles it around the bloodstream." (193) The problem now is that the particle, not the cholesterol, seems to be what is actually causing the problems; which the cholesterol is just an innocent bystander (Taubes, 193).
Interestingly enough, the LDL particle actually has some gradations in size to determine if it is causing a problem in our arteries or if it is fine. When the LDL particle is small and dense, they can work their way into the walls of our arteries and form plaques. However, when the LDL particle is large and buoyant, then it appears to be harmless (Taubes, 193). Consuming carbohydrates seems to cause LDL to become large and dense, while restricting carbohydrates does the opposite, making the particle larger and fluffier (Taubes, 194).
Metabolic Syndrome
When we eat diets high in carbohydrates, not only do we end up secreting much more insulin than is necessary in our bodies, but we also contract many metabolic disturbances as well; such as a rise in blood pressure, a rise in triglycerides, and a lowering of HDL. Additionally, LDL particles become more dense and smaller (Taubes, 195). The combination of these risk factors are what is referred to as metabolic syndrome.
Today, more than 1/4 of the population is considered to have metabolic syndrome. The main reason for this is that diabetes and obesity are considered among its symptoms, and we are experiencing epidemics of both (Taubes, 195).
The metabolic syndrome tells us that heart disease and diabetes are not caused by individual risk factors but by insulin resistance and elevated levels of insulin and blood sugar playing havoc with cells everywhere (Taubes, 197). Insulin works in the body to cause many different effects on different body tissues. It works on the fat cells to make us accumulate fat, on the liver to convert carbohydrates into fat, on the kidneys to raise blood pressure by absorbing sodium and by impairing the secretion of uric acid, and on the artery walls to stiffen them and cause the accumulation of triglycerides and cholesterol in the budding atherosclerotic plaques (Taubes, 197). While insulin is doing all of this, the elevated blood sugar in the body causes a state of oxidative stress and leads to the creation of advanced glycation end products which also cause artery walls to stiffen and a premature aging to take place (Taubes, 197).
Metabolic Syndrome Redux
In addition to cancers, obesity, and diabetes that are associated with the metabolic syndrome, Alzheimer's disease is also associated with the metabolic syndrome! Researchers believe that insulin and high blood sugar may cause the brain to deteriorate symptomatic of Alzheimer's (Taubes, 199).
In the end, Taubes says that it is vital that we reduce the amount of carbohydrates we consume; because it seems that "what makes us fat - the quality and quantity of carbohydrates we consume - also makes us sick." (200)
Following Through
In the final section of Taubes' book, he simply wants to talk about how best to avoid the carbohydrates responsible for weight gain and what else to do to maximize the benefits to our health (201). He suggests taking a look at some of the best-selling low-carbohydrate diet books out there in order to have some guidance; but more importantly to follow some ground rules. Taubes tells us to "eat as much as you like of meat, fish, fowl, eggs, and leafy green vegetables. Avoid starches, grains, and sugars and anything made from them (including bread, sweets, juices, sodas), and learn for yourself whether and how much fruit and non-starchy vegetables (such as peas, artichokes, and cucumbers) your body can tolerate." (203) Finally, Taubes writes to us about common questions with the low-carbohydrate diets in order to give us his best advice and answers.
Moderation or Renounce Them Entirely? Part 1
According to Taubes, "the fewer carbohydrates we consume, the leaner we will be." (204) However, it is important to remember that while we can control the amount of insulin secreted in our bodies through our diets, we cannot control the secretion of other hormones - estrogen and testosterone. Also, different bodies will behave differently. The amount of carbohydrate restriction that is needed to lower weight and fat accumulation differs greatly depending on your body. Some will only have to get rid of sugars in the diet, others will have to renounce carbohydrates entirely to have the same effects (Taubes, 205). Some, even still, may never be able to get back to their lean self - "a point of no return" as Wolfgang Lutz refers to it (Taubes, 205).
Taubes, however, believes that it is more a matter of strict adherence to the diet and patience that will eventually lead anyone to lower their fat accumulation and perhaps reverse its effects. He says that "reversing the process may take more than a few months or even a few years as well (206).
Moderation or Renounce Them Entirely? Part 2
Taubes tells us there are three main approaches to maximize the effect and sustainability of eating a low carbohydrate diet. The first is to "establish an ideal amount of carbohydrates that you can and perhaps should eat." (207) This approach assumes that it is easier to eat some fattening carbohydrates than it is to completely eliminate them. The second approach is to aim for minimal carbohydrates from the outset (Taubes, 207). Finally, the last approach is to create a compromise, such as that created by Dr. Robert Atkins: to temporarily eliminate carbohydrates and then eventually add them back in once a goal weight is achieved.
Diets that follow the third approach generally begin with an "induction phase" where dieters are allowed virtually no carbohydrates in the diet (only about 20 grams per day) (Taubes, 208). Then, when you have reached your goal, you can slowly add carbohydrates back into your diet. However, this can be a slippery slope. Carbohydrates, like cigarettes, are addicting. By letting them back in the diet, some dieters will be able to handle the cravings that come with it, but others may not be able to resist their addicting nature (Taubes, 208).
It is also important to not participate in semi-starvation diets. When eating diets low in carbohydrates, you have to compensate by eating meats, fats, and vegetables high in fiber. Many diets fail when they encourage a semi-starvation mode. They fail because your body adjusts to the caloric deficit by expending less energy, you get hungry and stay hungry, and you get depressed, irritable, and chronically tired (Taubes, 209). With the low-carb, high-fat diet, you will face some challenges - the hardest being a craving for carbohydrates. However, some research has shown that these cravings diminish and even disappear over time. So while some may be able to handle putting carbs back into the diet, many may have to allow no compromise in order to have long-term success (Taubes, 210).
What It Means to Eat as Much as We Would Like
Often, when restricting carbohydrates in the diet, dieters tend to eat less than usual. However, a common experience is to not feel as hungry as you used to when eating the fattening carbohydrate (Taubes, 211). In addition to not feeling as hungry all the time, your energy expenditure will also increase because you are no longer diverting your energy into your fat cells, but are storing it where it can be used to burn (Taubes, 211). While eating a low-carb diet, your body will naturally find its own balance between energy consumption and energy expenditure. Therefore, it is important to eat when you are hungry while on this diet and to only eat until you are satisfied (Taubes, 212)!
Fat or Protein?
While there is no compelling evidence saying that a high-fat diet is truly harmful, a diet of high protein without fat to accompany it can be toxic (Taubes, 213). Diets high in protein but low in both fat and carbs can cause you to have weakness, nausea, and diarrhea (Taubes, 213). In order to avoid these issues, it is vital to eat a diet high in fat along side a diet high in protein.
On Side Effects and Doctors
Initially, when you replace carbohydrates in the diet with fat, you will experience some side effects - mostly from a carbohydrate withdrawal. These side effects can be things like weakness, fatigue, nausea, dehydration, diarrhea, constipation, postural hypotension (standing up to fast and feeling dizzy), and exacerbation of preexisting gout (Taubes, 214). These symptoms come along because of a withdrawal from carbohydrates and can also exist if the diet is too high in protein. Because symptoms like these exist at the outset of a low-carb diet, it is important to always have the help and guidance of a knowledgeable physician when making the decision to go on a low-carb diet (Taubes, 216).
THE END - Thank you Gary Taubes for your wonderful and informative book on fat accumulation and what we can do to alter our diets in order to avoid it!
Exercise: Unfortunately, due to having to work a bit later today than I would have liked, I didn’t' actually have time to get to my Yoga class. Instead I decided to de-stress and take the day off. Tomorrow I'll be back to swimming though!
Eat: I want to talk about a final group of four fruits and their benefits today. Plums contain vitamin C and vitamin K. Dried plums, also known as prunes, contain fiber, iron, and vitamin K. Pomegranates have potassium and vitamin C in them. And finally, raisins contain potassium and fiber.
Relax: After a stressful day at work, I went out to grab a bite to eat with some friends/co-workers. It was super nice to chat and hang out! Now is bed time though and I'm so ready to just pass out.
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