Lose your belly: insulin control for fat burning

From a plastic point of view, the human body is very versatile and can take on a whole range of different forms. Even people who roamed the halls of high school at a young age with an athletically built body eventually achieve what is known in the Anglo-American world as a "dad bod". ("Dad Bod" is an abbreviation for Daddy Body and describes a body with little muscle and a slight tummy bulge). Is this the pinnacle of human development today? Men who look like the apple-shaped guy from the Fruit of the Loom underwear commercials? Normal-weight people are the minority, while overweight and obesity affect about two-thirds of the U.S. adult population. Beyond the social stigma and functional limitations these obese people face, there is a well-documented link between obesity and a number of chronic health problems that have reached epidemic proportions over the past half century: Type 2 diabetes, hypertension, liver disease, heart disease, and certain cancers in addition to other less prevalent ailments (1).

Obesity is sometimes defined by the fat deposits that are most affected. For example, many women develop a "gynoid" appearance with fat deposits primarily located in the hips, buttocks and thighs and may also include "chicken wings" that hang down below the upper arms. Surprisingly, this type of obesity is less harmful than the so-called "android" type. By "android" we do not mean a fast-food consuming robot, but the typical man with a belly that hangs over his belt like a wide fleshy tie. These appearances are also referred to as apple-shaped and pear-shaped.

Visceral obesity (fat around the internal organs) is basically the same as truncal obesity, which is pretty much the same as "android" obesity. Some men have a big belly due to excessive amounts of subcutaneous fat with little visceral fat, but this is the exception rather than the rule. Furthermore, fat can also be deposited in certain organs and not just around them. The liver is a vital organ. If fat accumulates in the liver, it no longer functions properly and can send out inflammatory signals that promote disease and cause an altered hormone metabolism. There is a condition known as "non-alcoholic fatty liver disease", which affects up to a third of all American adults and describes metabolic impairments that occur as a result of a "fatty liver" (2).

So there are more than just cosmetic reasons why a slimmer waistline and healthy body composition should be the goal of every sensible person. A slimmer waistline and healthy body composition can help maintain or regain overall health and healthy metabolic function and prevent premature death. Visceral obesity is closely related to the metabolic disorders listed above that are associated with obesity and the role of chronic inflammation is believed to be a linking factor (3). Recent research suggests that the flora of gut bacteria, known as the microbiome, may play a significant role (4).

Although bodybuilders are amazingly adept at modifying their bodies and reducing both body fat and waist circumference to a physiological and anatomical minimum, the general public struggles with this. As things currently stand, gastric bypass surgery is recommended for severely obese people to achieve significant and sustained weight loss. Obviously, this involves high cost and high risk.

The power of fasting

Recently, several studies have reported the effects of individualized nutritional regimens rather than dieting on visceral obesity. Most diets focus on how much a person eats or perhaps the macronutrient ratio(carbohydrate: protein: fat), as is the case with the Zone diet, the Atkins diet, the South Beach diet and other ketogenic diet programs. These diets rely on restoring the body's sensitivity to the hormone insulin and reducing its fat-promoting properties by reducing the carbohydrate content of the diet and lowering the glycemic index or glycemic load. But there is a proposed solution that could be even simpler and is related to when a person eats. The concept of fasting is similar and relates to a period of time during which a person does not eat. Obviously, although this will help to reduce weight, it is not a long-term solution as the body will start to break down lean body mass to meet energy needs and both physical and cognitive performance will suffer. Prolonged fasting can also lead to suppression of immune function, bone loss, organ damage and eventually death (5). Nevertheless, the power of fasting can be harnessed in judicious doses to deliver many of the fat loss benefits without loss of lean body mass or compromised health. This has been demonstrated in animal studies and there is also a limited amount of human data (6). Unfortunately, there is no standard timing scheme, so this approach is still in its infancy.

Different terms including 'intermittent fasting' and 'alternate-day fasting' have been used to describe the regimens that have been used in published studies. Time-restricted eating involves limiting eating to a set number of hours per day, during which you can eat pretty much anything you want - but only within a four to eight hour window. Alternate-day fasting is exactly what it sounds like - you eat whatever you want one day and fast the next (consuming about 25 percent of maintenance calories on the fast days) (7).

Without limiting the amounts a person may eat on any of the non-fasting days, it sounds like these diets are structured to promote epidemic binge eating disorders. However, the limited research on this topic seems to show that even when people eat more on non-fasting days, the additional amount is not that much higher than normal and becomes less and less over time, and food intake eventually tends to level off at the normal daily calorie intake (8). This means that the calories "avoided" by fasting can be more or less subtracted from the weekly calorie intake and fasting on alternate days can lead to a significant calorie deficit over time.

Most studies cited on alternate-day fasting showed an average weight loss of 6.5 percent over eight weeks (9). Intermittent fasting involves a less extreme variance in calorie intake but still appears to lead to a reduction in calories consumed each week. Both approaches appear to maintain lean body mass, while most of the weight loss can be attributed to a reduction in fat (10). In addition to the long-term caloric deficit that accumulates during fasting days, there also appears to be an increase in the release and utilization of stored fat, an adjustment in metabolism and physiology to utilize stored reserves (fat) to a greater extent and more efficiently, and a positive change in cardiovascular markers of health that suggest further health benefits (6, 7). For people who want to lose "belly fat", these diets may be the optimal solution. Animal and human studies show that fat loss is the same for both approaches, with little or no loss of lean body mass.

The Mediterranean diet, olive oil and insulin sensitivity

The aforementioned optimizations can be easily integrated into most diets and nutrition plans. The first thing you should do is make wise food choices, even if you are allowed to eat whatever you want. Animal studies show that intermittent, phased food intake induces fat loss while maintaining lean body mass and is associated with changes in brain chemistry that may combat a slowdown in metabolic rate often seen with calorie restriction while avoiding hunger issues (11). In terms of these "wise" food choices, following the Mediterranean dietary style appears to be an option. A key component of the Mediterranean diet is olive oil, which is rich in the monounsaturated fatty acid oleic acid. Three diets were compared in a study that followed 11 insulin-resistant people with a family history of type 2 diabetes (12). The diets, which each subject followed for 4 weeks before moving on to the next diet after a short break, were rich in saturated fat, monounsaturated fat or carbohydrates. All the diets considered contained only 15 percent protein and were designed to maintain body weight. In the end, it was clear that the high-carbohydrate diet (65%) had the least benefits and caused a redistribution of body fat towards the abdomen. This has particular relevance for men who experience "android" fat distribution when they gain weight.

The diet rich in olive oil produced better insulin sensitivity and lower adipokine levels. Diets rich in saturated fats have been reported to reduce insulin sensitivity (13). Adipokines are fat cell hormones that increase calorie burning, suppress appetite (leptin) and improve insulin sensitivity (adiponectin) in a healthy person. However, when fat cells become excessively large or resistant to regulatory signals, the levels of these adipokines increase in an unhealthy way. This is why studies looking at obese people see reductions in these adipokines, and this is a positive change, unlike the same change in a lean person.

Imagine a person shouting to get their point across in a discussion by speaking louder and their message is clearer when they speak louder. And now imagine a person who is hard of hearing who can only follow a conversation when someone is shouting and even then cannot understand everything properly. If the hard of hearing person gets a hearing aid, the conversation becomes quieter - not because the speaker doesn't want to communicate, but because the ears work better. With weight loss or a better diet, adipokines no longer have to "shout" so loudly in obese people. More exciting than the changes in the lab reports, however, was the discovery that the olive oil diet prevented the fat redistribution toward the abdomen that was observed with the high-carbohydrate diet. This suggests that a low-carbohydrate diet with added olive oil in conjunction with intermittent fasting or fasting on alternate days may be best for reducing abdominal fat.

As with any diet, this could be the "one" diet or a diet that is not tolerated. Certainly the early research regarding these "when" diets versus "what" or "how much" diets is promising. Incorporating lessons already learned - such as reducing carbohydrates, limiting saturated fat consumption and incorporating olive oil - could increase the power of these programs in terms of promoting health and reducing waist size. The convenience of watching the clock, rather than the calorie count, certainly has its own charm.

References:

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