The Fat Switch

by Richard J. Johnson

Role of Fatty Foods and Trans Fats. The fat switch, activated by sugar and umami foods, acts primarily to change body composition to increase fat stores, and to make one leptin resistant so one is predisposed to gain weight. If one is eating a lot of sugar, then high fat diets will have a role in weight gain. However, by restricting foods containing added sugar and umami foods, the effects of high fat diets to increase weight are mild or absent. Furthermore, the Atkins diet has shown that when carbohydrates are restricted, weight loss can occur even when a person is eating a diet high in fat. As such, it is not important to restrict fats if one is on a diet low in added sugars and HFCS. However, some studies suggest one should avoid eating foods containing trans fats, as these can increase serum cholesterol and risk for heart disease.

Dairy. There are also foods that have beneficial effects on obesity and metabolic syndrome. Diets high in dairy products, such as milk and cheese, are associated with reduced risk for obesity, diabetes and gout.18 The exact reason for the benefit is not known, but may be due in part to the fortification of dairy products with vitamin D, coupled with the ability of dairy foods to reduce serum uric acid levels.19-20 Unfortunately, some people cannot tolerate dairy products due to the presence of lactose intolerance, in which they develop abdominal pain, gas or diarrhea with dairy products. Nevertheless, for those who do tolerate dairy, increasing ones intake of milk and cheese is likely beneficial to overall health.

Coffee. Coffee is a stimulant and is one of the most favored drinks in the world. While coffee drinking can be associated with some undesirable side effects, such as diarrhea, reflux, and benign cysts in the breast, coffee also has some health benefits. The greatest benefit appears to be to decrease the risk for diabetes.21-23 Numerous studies have shown that heavy coffee drinkers, who drink four to five cups of coffee a day or more, reduce their risk for developing diabetes by 50 percent, which is a quite remarkable feat. The reason why coffee prevents diabetes is not known. However, a likely explanation is that heavy coffee drinking reduces uric acid levels. Heavy coffee drinking is associated with lower serum uric acid levels,24-26 likely because one of the metabolites of coffee is 1-methyl xanthine that competitively inhibits the enzyme (xanthine oxidase) that produces uric acid.27

The first recommendation is to take vitamin C, 250 milligrams twice per day. Vitamin C is an antioxidant that combats many effects of fructose, and it also lowers uric acid.28 As such, it helps turn off the fat switch.

The only problem with vitamin C is that there is some data that at high doses (1 gram daily) interferes with the recovery of mitochondria that occurs with exercise.29 This is why I would limit the dose to 500 mg daily

For the performance athlete, I would avoid vitamin C entirely and rely on diets rich in fruits.

I also recommend taking 1000 IU (or 25 micrograms) of vitamin D daily. A lack of vitamin D may not only affect the health of our bones, but also increase our risk for high blood pressure and heart disease. Some studies suggest that as many as 5 to 10 percent of adults are deficient in vitamin D.30 Some of this is due to reduced exposure to the sun, since sunlight can stimulate vitamin D synthesis in the skin. However, vitamin D deficiency is more common in people who are obese or have metabolic syndrome, occurring in up to 75 percent of these children or adults.

Jack Lalanne once said, “If it tastes good, spit it out,” and he is also famous for stating that the “only good thing about a doughnut is the hole.”

At one level, this is because our taste buds encourage foods that are sweet, savory (umami), or salty and warn us for tastes that are bitter and sour. This love for these types of foods occurred because they all have the ability, at some level, to turn on the fat switch, and hence encouraging an animal to seek these types of foods was beneficial for survival.

Sports drinks contain small amounts of fructose and can enhance performance.

Obese people and those desiring to lose weight should perform hard work before food . . . Their meals should be of a fatty nature as people get thus satiated with little food. They should, moreover, eat only once a day and take no baths and sleep on a hard bed and walk naked as long as possible. —Hippocrates (from Procope J. Hippocrates on Diet and Hygiene, Zeno, London, 1952).

Losing weight requires both blocking the fat switch and reducing glycogen stores so one can burn fat.

As we have discussed, weight is normally tightly regulated. However, many of us have become mildly leptin resistant, which we believe is being driven largely from diets high in sugar. As a consequence, most of us are slowly gaining weight, with an average increase of one or two pounds per year. This only requires taking a few more calories each day over what we require to stay in balance. Some studies suggest that this amount equates to only 15 extra calories a day on average. However, as one gains weight, one also requires more energy to stay at that new weight. Thus, once you are at a higher weight, you will eat more calories to stay at your new weight, plus you are also likely to eat additional calories above your needs because you will continue to be leptin resistant. This emphasizes why losing weight is much more challenging than preventing weight gain. This is because to lose weight you have to not only restrict the extra calories you eat each day, but also you have to restrict calories to the point that your calorie intake is less than your energy demands. This is further complicated by the fact that there will be a tendency for you to reduce your energy output as energy ...

One of the simplest ways to reduce glycogen in the liver is by fasting. Indeed, fasting during the day or for 24 hours is common in some religions. However, this is not easy to do for any sustained period of time.

an approach I like to use capitalizes on the fact that glycogen is rapidly depleted in the liver while we sleep, and after an eight-hour sleep the stores of glycogen are low. Thus, in the morning we are in a fat-burning mode, and this explains why exercising in the morning on a fasting stomach is more effective at burning fat than later in the day.50-51

an effective way to lose weight is to allow the burning of fat to continue during the day by avoiding breakfast or limiting it to only protein and fat (such as an egg or meat). When I want to lose weight, I avoid breakfast and drink coffee with milk to help control my appetite during the morning. For lunch I avoid all carbohydrates and will have only a salad, occasionally with chicken or other meat. If I am hungry, I might eat some dark chocolate (see next chapter) or a natural fruit. At night, I relax my diet and eat a regular meal, although I tend to be sparing on carbohydrates and especially sweets. I also do not snack after dinner, and I prefer to have dinner early in the evening. This way I can start to burn the glycogen stores even before I go to sleep. This approach usually results in effortless weight loss.

While originally this was attributed simply to the burning of calories, experimental studies have shown that exercise blocks both the drive to eat and also helps reverse the defect in fat oxidation.5 In other words, exercise may be one way to help reverse the fat switch.

The reason exercise is so effective likely relates to its ability to stimulate the production of new mitochondria and the generation of ATP.64

Exercise helps to reverse these effects by increasing the number of mitochondria. With more ATP produced, there is more energy, and this may have a feedback to reduce food intake. If the mitochondria number returns to normal, you will have the best chance to reduce your weight and keep it off.

Exercise in the morning, or in a fasting state, burns fat faster.

The historical recommendation has been to perform aerobic exercise for 30 minutes each day, but more recent studies suggest that short episodes (3-4 minutes) of high-intensity exercise may be the most beneficial way to reverse insulin resistance and improve overall health.

High intensity exercise involves exercise that increases your heart rate to 90-100% of maximum for 30 seconds, followed by 90 seconds of rest for eight cycles. This can be done two to three times per week and may be the most beneficial way to reverse insulin resistance and improve overall health.

In this book we have presented evidence that weight is normally tightly regulated and stable. To change to a higher weight, animals must stimulate oxidative stress in their mitochondria, or energy factories, in which the energy that is ingested from food is preferentially shunted to fat as opposed to ATP. The low ATP state causes fatigue and further stimulates food intake. Leptin resistance also develops, leading to more food intake that helps to recover the ATP levels at the expense of increasing fat stores. The relative shunting of energy to fat leads to an accumulation of fat in the liver, blood and abdominal viscera, and insulin resistance develops.

One of the best ways to stimulate mitochondria growth is by exercise,

Science is not an absolute truth but is a moving field and based on models, or hypotheses, that provide the best explanation to account for the observations of the time.

Science is not an absolute truth but moves forward based on models that both explain and predict observations.

As Darwin wrote, “It is not the strongest of the species that survives, nor the most intelligent that survives. It is the one that is the most adaptable to change.”37

As one reflects on this story, one realizes how fortunate we were to have acquired these mutations. Extinction is a common event. There have been at least five massive extinctions that each led to the demise of more than 50 percent of species living at that time.38 Recall that during the Miocene there were 100 different ape species, for which only 5 survive today.39 Consider the fact only Homo sapiens survive today, and related species in our genus, such as Home erectus, Homo antecessor, Homo heidelbergensis and Neanderthals (Homo neanderthalensis) no longer walk the earth. We are lucky to be alive.