Various schools of thought continue to evolve about the type and amounts of foods that we need to not only achieve and maintain a proper body composition, but to be healthy as well. As much of the Western world faces the challenge of the overweight/obesity epidemic, consumers are still looking for answers related to how to properly and sustainably lose weight.  One thing seems to be pretty certain:  we cannot exercise our way to weight loss.  For someone who is overweight, it is nearly impossible for that person to exercise for a suitable duration at an appropriate intensity every day to burn enough calories to achieve a healthy body weight.  Thus, the amount and type of food are far more important compared to exercise for achieving a healthy and sustainable body weight.

When it comes to the type of calorie, we know that certain foods activate hormonal responses that lead to hyperglycemia, hypertriglyceridemia, hyperinsulinemia, and other hormonal consequences that lead to insulin resistance, metabolic syndrome, and eventual obesity, type 2 diabetes, and/or cardiovascular disease. Simple sugars, such as fructose, glucose, and high-fructose corn syrup, are the best examples of carbohydrates that lead to these metabolic problems and contain no redeemable phytonutrient content and/or other nutritional value.  Unfortunately, these sugars are widely used in all types of processed and manufactured foods today.  Without any other nutritional value, they are sources of “empty” calories that only serve to increase the phenomenon of the average person being “overfed and undernourished,” which has predominantly lead to the obesity epidemic that plagues the world today.  However, consumption of carbohydrate is very important, as the body primarily supplies energy to itself through the utilization of glucose or “blood sugar.”  Eating plenty of complex carbohydrates (polysaccharides and oligosaccharides) should be part of your regular diet, and you get many of these sugars from vegetables, grains, nuts, and seeds.  Although fruit contains fructose, which has been shown to be related to a risk of metabolic syndrome, it also has many important vitamins, minerals, and other phytochemicals, such as vitamin C and carotenoids, that are not as prevalent in other foods.  Thus, including fresh or frozen fruit is part of an overall healthy approach to eating to get those key nutrients.

Types of fats can be problematic as well. A growing body of literature suggests that trans fats lead to atherosclerosis and may in fact be carcinogenic as well.  Trans fats are liquid fats that have been (partially) hydrogenated to turn them solid at room temperature.  Thus, they are cheaper for production processes and enable food manufacturers to increase the shelf life of certain products, such as breads, cakes, and cookies, where these fats are commonly found.  Growing consumer awareness of the problems associated with trans fats caused governments to require that food companies label their foods with the amount of trans fat in their products, although one loophole in this label requirement exists.  If a food contains less than 0.5 g per serving of trans fat, then the label can state that it contains “0” trans fat.  Thus, you need to read your label to see if any ingredient is listed as “partially hydrogenated” or “hydrogenated” fat of any kind.  If that ingredient is on the label, then you know that the product contains some trans fat.  Saturated fat has been historically shown to be related to an increased risk of cardiovascular disease primarily and to other diseases, such as different types of cancers, as well.  Polyunsaturated fats, such as omega 3 fatty acids, are being increasingly recognized for their benefits for everything from heart and brain health to improving mood disorders.  Monounsaturated fats are also healthy fats that provide superior benefit compared to saturated fats.  All types of fats have approximately 9 calories per gram, so it is important to consider how much fat to include in the diet when regulating the number of daily calories for proper weight management.  Additionally, choosing the right type of fat is extremely important in terms of the benefits derived for heart and brain health, among other important considerations.

Finally, the type of protein you consume is also strongly related to certain metabolic consequences or health challenges. Casein, which is about 80% of the protein in cow’s milk, has been found to be particularly carcinogenic in both animals and humans.  Eating processed red meat, especially if it is grilled, fried, or cooked at very high temperature (above 375 °F), has been labeled by the World Health Organization as probably carcinogenic and should be limited, if not avoided entirely, in the diet.  New carcinogenic chemicals are being identified as problematic from eating cooked animal food (sources of protein and fat).  For example, heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs) are chemicals formed when muscle meat is cooked with high heat.  HCAs and PAHs have been found to be mutagenic that cause changes (not the good kind) in our DNA.  Trimethylamine (TMA)-containing dietary compounds in meat, milk, and other animal foods are converted by gut bacterial TMA lyases to TMA, which is absorbed and converted predominantly by flavin mono-oxygenase 3 to the toxic trimethylamine N-oxide (TMAO).  TMAO causes atherosclerosis in animals and is elevated in patients with coronary heart disease.  Phosphatidylcholine, mainly derived from eggs, red meat, and fish, is the major dietary source for TMAO.  Higher phosphatidylcholine consumption is associated with increased all-cause and cardiovascular disease mortality.  Thus, getting your protein from plants (vegetables, nuts, seeds, grains, and even fruits) primarily eliminates these problems, allowing you avoid elevated risk of cardiovascular disease, cancer, and other chronic diseases.  Make sure to eat your plants fresh and if you cook them, avoid overcooking them for extended periods of time.

In summary, a “calorie is a calorie” is really only true when you are calculating the amount of calories you consume per day and then compare that to your basal metabolic rate (the number of calories burned during rest) plus the number of calories expended during activity. Theoretically, if you eat fewer calories than you burn every day and hit that target consistently, then you would likely lose weight.  However, to optimize your health, you need to not only consider the amount of calories you are consuming, but which food sources are contributing to your diet and overall caloric intake.  The best recommendations for optimizing body weight and health would be to eat a moderate amount of calories (not exceeding your basal metabolic rate plus the amount of calories burned during activity) and limit or entirely eliminate the following:  (1) simple sugars like high-fructose corn syrup, (2) trans fat, and (3) protein from animal sources.  Implementing these strategies will ensure that you maintain a healthy body weight and greatly reduce your risk of chronic diseases associated with obesity, like cardiovascular disease, type 2 diabetes, and various forms of cancer.