Mar 28, 2012
Our Fat Pets (and what we can learn from them)
Every week, I read a lot of scientific articles (a LOT) in an effort to stay “up” on the latest research in nutrition, metabolism, and human performance. Most of the research that I focus on is about humans—or sometimes analytical “test tube” studies that relate to human metabolism in certain ways. Every once in a while, I’ll delve into some of the research studies published in animal science journals, because there are often observations about how animals eat and how they respond to changes in their diet that can be instructive for similar dietary changes in humans.
I thought that you might find two recent articles as interesting as I did. One was about obesity in dogs and cats (Journal of Animal Science, Oct 2011), and the other was about the “stress” that rats experience when their diets are changed from high calorie to low calorie or vice versa (Physiology & Behavior, Nov 2011).
Studying animals and how they respond and adapt to dietary changes can sometimes be even more interesting than studying the same things in humans. Why? Because animals are less susceptible to many of the “confounding factors” (factors that interfere with what you’re actually trying to study) that can influence studies of humans. For example, your dog is less susceptible to an advertisement for Big Macs or Coca-Cola than you are; and, your cat is less likely to feel “deprived” by only having one Oreo instead of the whole box.
Fat Cats (and Dogs)
When you look at lifelong studies of dogs and cats (as in the Journal of Animal Science study), there is a clear indication that fatter pets have more health problems, require more medications for chronic health problems (and need the drugs sooner), and die earlier when compared to normal-weight pets. Whether your dog or cat is moderately overweight or obese, they clearly have an increased risk for arthritis, diabetes, liver problems, and premature death—just like what we see for us humans. For example, overweight cats have double the risk for diabetes (compared to lean cats) and obese cats have a risk of 8-times!
Obesity and Inflammation
For many of the same reasons that being overweight is bad for human health, having too much adipose (fat) tissue is also bad for animal health. One of the most important reasons is that we want to avoid (or reduce) excess adipose tissue is because it is an active producer of hormones (leptin, cortisol, resistin) and cytokines CRP, TNF, IL-6, etc) that can lead to chronic low-grade inflammation throughout the body. This inflammation can lead to a variety of problems with cellular function, including free radical damage (“oxidation”), blood sugar problems (“glycation”), and cellular stress (cortisol/testosterone balance) that can eventually cause or exacerbate diseases such as osteoarthritis, diabetes, heart disease, and even a furthering of obesity. In many ways, it is hard to even identify a disease of modern life that does not have inflammation as a defining factor.
Dieting Dogs and Stressed Rats?
OK, at this point, you might be thinking to yourself that I haven’t told you anything that you didn’t already know. You already knew that being overweight wasn’t good for long-term health, and you might have even heard something about the obesity/inflammation connection. You also probably knew that your dog or cat could stand to lose a few pounds (same for lots of us, right?), but how do you actually go about making that happen? Is it as simple as feeding Fido fewer biscuits? Unfortunately, no.
Think about what happens to us when we try to lose weight by “dieting.” We might cut back our food intake or switch to a lower-calorie diet, but soon we’re feeling stressed, hungry, and grouchy. The same thing happens in animals, as the study in Physiology & Behavior shows us—and it gives us some insight into how our metabolism is likely to respond when we “diet” for weight loss. In this study, rats were fed either an “energy rich cafeteria diet” (basically a rodent version of fast food that is high in fat and sugar, and that they eat a lot of because it tastes good) or fed a healthier “chow” diet with fewer calories, less fat, more fiber, etc. (basically a rodent version of lean proteins, low-glycemic carbs, and lots of fruits and veggies).
As you might expect, when the rats were given the “fast food” diet, they ate a lot and quickly gained weight (gaining almost 30% more weight than the “chow” group after 4 months). Interestingly, the fast food rats also had significantly higher levels of dopamine and the main enzyme that helps make more dopamine (tyrosine hydroxylase). Dopamine is one of the body’s primary and most potent “feel good” chemicals (many illicit drugs such as cocaine and methamphetamine act directly on the brain’s dopamine system), so this study shows us that the high fat/sugar content of “fast food” generates an “addictive” response in the brain (it’s no wonder that “comfort food” is so comforting).
When the rats were switched from the “fast food” diet to the healthier “chow” diet, they lost significant amounts of body fat (-16%) and improved blood sugar control (-22%), in addition to optimizing metabolism in numerous ways. Unfortunately, these same rats also showed a stimulation of their body’s stress response (higher levels of stress hormones like corticotropin and cortisol)—reflecting the “stress” of the abrupt change in diet from junk food to healthy food. This doesn’t mean that eating a healthier diet is “more stressful”; rather, it indicates the difficulty of “coming off” of an addictive fast food diet and adhering to the healthier choices. We know from related studies that overexposure to stressful events and excess stress hormones can stimulate appetite and lead to weight gain (especially in the abdominal or “belly” region)—in effect using your body’s own biochemistry to “drive you back” to eating junk food.
What These Studies Mean for You?
You might be asking yourself what fat cats and stressed rats have to do with you? These studies show us quite clearly that being overweight and having excess body fat is detrimental to long-term health, and also show us that typical “fast food” type diets can be both highly addictive (the dopamine data) and extremely “stressful” to break away from (the corticotropin data).
In today’s world where we’re surrounded by both stress and fast food, a big part of the “solution” to managing body weight is to eat meals that (1) taste good, (2) help balance metabolism and blood sugar, and (3) do not feel restrictive like a diet. The MonaVie RVL products have an excellent balance of protein, fats, and carbohydrates that not only taste delicious, but also help keep you satisfied longer.
About the author: Shawn Talbott is VP of Research & Product Development for MonaVie. He holds a MS in Exercise Science, a PhD in Nutritional Biochemistry, and is the author of 10 books, including "The Secret of Vigor" (Hunter House, 2011), about natural approaches to restoring mental and physical energy levels. He has two dogs—Morgan and Mimi—who are both lean and fit and who easily leave him in the dust on their morning trail runs.