Why the food supply, gut bacteria, and NON caloric items can be causing weight gain!

When it comes to weight loss it was once as easy as calories in vs. calories out. Consume less than what your body needs to maintain its current weight and voila the weight comes off.  While once an effective strategy it’s doesn’t always work now.


While this method doesn’t always work it doesn’t mean that portion size and exercise aren’t important. Reducing food intake and exercising more can still have dramatic improvements on weight loss. In fact a large percentage of individuals will still lose weight with the traditional recommendation of exercise more and eat less.


However if you’ve tried exercising more and eating less and it’s not working there are several reasons as to why this could be happening. Some are easy to fix and understand and others not so much.  In addition the research is still coming in so we do not have all the answers. So if you’re someone who has tried many diets with limited success – read on!


While this article is designed to provide possible culprits for lack of weight loss – it is not an exhaustive study. I would encourage you to take this information and read for yourself – there are multiple sources at the end of the article that go into greater detail on many of the topics. Here are some of the most common reasons individuals are not losing weight even when exercising more and eating less.


FOOD SUPPLY (antibiotics, hormones, pesticides, GMOs)


Over the last few decades food manufacturers and growers have started altering the food supply. In order to boost up profits they are giving animals antibiotics with the hopes of keeping them healthier (and bigger). These antibiotics are then passed onto humans and can have a negative affect in our gut bacteria (we’ll discuss later) and an increase in weight gain (not to mention there is evidence that children who take a lot of antibiotics tend to be more overweight). The widespread use of antibiotics has ramped up in the last few decades and coincides with the increase of obesity in our nation.  


In addition to antibiotics cattle are given hormones (chickens are not given hormones so packaging that says hormone free for chicken isn’t necessary). These hormones cause the animals to bulk up much quicker.  Many experts believe that when we consume or drink the milk from the dairy cattle it can cause weight gain. For example a study in the International Journal of Obesity from researchers at 10 different universities, including Yale University School of Medicine and Johns Hopkins University, found that the use of steroid hormones in meat production and on conventional dairy farms could be a possible contributor to the obesity epidemic.


In order to combat the possibility of artificial weight gain consume meats that are raised without antibiotics, hormones, and grass fed. You can find hormone free. grass fed meat at many supermarkets.  Also choosing wild caught fish (i.e. salmon) would be a better choice than farm raised.


In addition to hormones our food supply can contain pesticides. Besides being unhealthy for consumption they can alter our endocrine system and mimic estrogen (Source: CBS news). Estrogen which is a female hormone can undermine our ability to build muscle and aids in fat storage.


While pesticides are in our food supply we can lessen our intake. According to a recent study in the journal – Environmental Health Perspectives, eating the right fruits and vegetables and avoiding the most contaminated ones, for just five days can reduce circulating pesticide based obesogens (foreign chemical compounds that disrupt normal development and balance of lipid metabolism, which in some cases, can lead to obesity).


The fruits with the highest pesticide content are apple, pears, peaches, imported grapes and strawberries. Buying organic can help reduce pesticide consumption. In addition fruits with skin are usually less of a concern because the pesticides does not usually penetrate it (i.e. bananas, oranges, grapefruit, etc.).


Apart from the use of pesticides food manufacturers have begun modifying foods in order to enhance production and profitability. These genetically modified foods (GMOs) have raised eyebrows because of their potential health consequences. In fact researchers from Norway fed food containing GM corn to one group of rats and food containing non-GM corn to another group. Over the course of 90 days, the rats on the GM-corn diet grew fatter and ate more food than the rats on the non-GM diet. The researchers also noticed that rats got fatter when they ate fish that had been raised on GM corn.


As the public has become more aware of the controversy surrounding GMOs manufacturers have started to make changes. In fact you can find many foods that say non GMO and there is an organization the “non GMO project” which has the stated goal of providing non GMO labeling.



Hormones play a large role in how our body functions, including metabolism. If there is something amiss it can result in significant difficulty losing weight. Some of the most common hormonal culprits are growth hormone deficiency, low testosterone, and an underactive thyroid.

According to webmd signs of an underactive thyroid include: fatigue, changes in menstrual cycle, sensitivity to cold/cold hands, dry skin, fatigue, constipation, and difficulty losing weight. Signs of low testosterone and/or low growth hormone can include: fatigue, depression, loss of muscle mass, increase in body fat, and mood changes.  If you suspect these might be hindering your body’s ability to lose weight have your levels checked. An endocrinologist can provide you with a full panel of levels determining highs and lows. They can then incorporate ways to balance out levels. In addition there are many physicians who specialize in hormone replacement therapy.




HFCS is chemically similar to table sugar and is found in a variety of foods.  The most common source is sodas, however it can also be found in cereal, bread, ketchup, yogurt, fruit juice, and a variety of other foods. It has been widely added to foods and drinks over the last 40+ years and correlates with the rise in obesity over the same time frame.


For years HFCS was considered to be equal to table sugar, however that perspective is changing. For example a Princeton University research team has demonstrated that all sweeteners are not equal when it comes to weight gain: Rats with access to high-fructose corn syrup gained significantly more weight than those with access to table sugar, even when their overall caloric intake was the same.


The first stop on limiting HFCS is to eliminate all sodas from your diet. In addition start reading your labels and find out what foods you typically consume that have them. Also for those with a sweet tooth stevia is a natural sweetener that has become more popular in recent years and can now be found in more products and even in many restaurants.  




According to wikipedia Gut flora (gut microbiota, or gastrointestinal microbiota) is the complex community of microorganisms that live in the digestive tracts of humans and other animals. According to many experts including the gut health project – poor gut health can increase the risks of a variety of ailments. Importantly it appears to play a role in obesity.


Research shows that obese people have a different mix of bacteria in their gut than lean people. Researchers led by Jeffrey Gordon, a biologist at Washington University in St. Louis, Missouri, set out to find direct evidence that gut bacteria have a role in obesity.

The team took gut bacteria from four sets of human twins in which one of each pair was lean and one was obese, and introduced the microbes into mice bred to be germ-free. Mice given bacteria from a lean twin stayed slim, whereas those given bacteria from an obese twin quickly gained weight, even though all the mice ate about the same amount of food.

Since it appears that there is a correlation between gut health and obesity many individuals have looked for solutions to help restore their gut flora. One way to help restore a healthy gut is by taking probiotics and/or increasing consumption of fermented vegetables (i.e. sauerkraut, beets, etc.) or cultured dairy products (i.e. keifer, yogurt, etc.).



Having the right amount of fiber in your diet is important. The American Heart Association recommends 25-30 grams daily. The average American gets about 15 grams per day. Consuming plenty of fiber will help you feel fuller longer, stabilize blood sugar, and block the absorption of some extra fat and calories.


Some foods that are high in fiber include beans, lentils, artichokes, peas, avocados, raspberries/blackberries, and bran. In addition there are some protein bars like quest bars, specially made breads (i.e. low carb tortillas/high fiber breads) and cereals like Kashi Go Lean which are very high in fiber.




Two Thirds of the body is made up of water and being adequately hydrated is an important part of keeping the metabolism functioning properly. Dehydration can affect the body’s metabolism – decreasing the ability to burn fat. It also tends to contribute to excess calorie consumption leading to fat being stored on the body, including the stomach. To highlight the importance of drinking water there a study was published in the Journal of Clinical Endocrinology and Metabolism which showed that the metabolic rate increases by 30 percent after drinking 2 cups of water.


Since water is an important part of a weight loss strategy – how much should we drink? There is no easy answer as lifestyle, age, sex, and body mass can all play a role. While there are multiple factors at play The Institute of Medicine determined that an adequate intake (AI) for men is roughly about 13 cups (3 liters) of total beverages a day. The AI for women is about 9 cups (2.2 liters) of total beverages a day. While it does list total beverages it should be mentioned that coffee, sodas, and black tea have a diuretic property so whenever possible water should be consumed.




Dr. Rick Tague highlights three reasons that vitamin/mineral deficiencies can cause weight gain. First we’ll have more cravings because our body is lacking the vitamins and minerals our body needs and cause us to eat more. Second it can cause fatigue, which leads to less calories being expended. Thirdly it can slow the metabolism – not having the right nutrients will cause our body chemistry to be off – limiting our bodies ability to burn sugar and fat.


Some common deficiencies that can affect weight gain include vitamin D, magnesium, calcium, and iron. Eating a well balanced diet and asking your doctor about the possibility of taking supplements is worth considering.




There’s a long list of medications that can cause weight gain. While not always possible to stop taking certain medications it is a good idea to check if it’s potentially causing weight gain.  While not an exhaustive list – if you’re taking antihistamines, birth control pills, steroids, diabetes medications, beta-blockers, psychotherapy meds, anti-seizure meds, breast cancer medications, some treatments for rheumatoid arthritis, and even some migraine and heartburn medications, may increase weight.



Recently there has been debate over whether food allergies may be causing you to gain weight. These are not the same as individuals who can go into anaphylactic shock when eating peanuts. These are allergies that can cause inflammation in the body leading to excess weight. Dr. Mark Hyman has seen his patients lose weight when cutting out specific foods. For more detailed information about how food allergies and gut flora may be causing weight gain please check out the following video link: http://drhyman.com/blog/2010/06/01/food-allergies-are-they-making-you-fat/

Some of the most common food allergies causing weight gain include dairy, grain, sugar, grain fed meat, and bad fats like hydrogenated oils. Another way to look at your specific food allergies is through the ALCAT test. Many individuals believe this test can help uncover foods that trigger chronic inflammation and weight gain. Following an ALCAT diet is limiting or cutting back on the foods that have been shown to cause a reaction in your body.


While plastic packaging containing BPA wouldn’t be on the top of the list for possibilities causing weight gain it shouldn’t be ignored. In a study published in the journal Nature, Harvard and Brown University epidemiologists compared levels of BPA in the urine of almost 1,000 U.S. women to their self-reported weight gain over a 10-year period, and the women with the highest levels of BPA reported gaining about half a pound more per year than women with the lowest levels.




While beyond the scope of this article to go into great detail on food choices it is worth mentioning a few things. First a higher protein lower carbohydrate diet seems to be more effective, especially for those who struggle with weight control. In addition limiting calories, drinking plenty of water, and eating at regular intervals can be helpful. For more detailed information on fat loss check out my blog at http://freedom4lifefitness.com/latest-fat-loss-research/



I realize this information can be overwhelming and you might not be sure where to start. Also while the information could be helpful and healthy it is mainly designed for those individuals who are exercising regularly and keeping their caloric intake somewhat low. Calories should be kept at or below where they need to be to lose weight (there are many apps including myfitnesspal that can determine your calorie intake based on your activity, goals, and age).

If you have diligently tried losing weight and it’s not coming off here’s some things that may help:

  • Consider having your hormones tested, especially if you suspect this and are over 40.
  • Try consuming organic foods, hormone free/grass fed meats, avoid GMOs, and eat wild caught fish vs. farm raised.
  • Avoid common inflammatory foods like dairy, grains, and sugars. Also avoid processed foods whenever possible.
  • Eat foods to restore gut health and/or take probiotics.
  • Check your medications to see if they are potentially causing weight gain.
  • Drink plenty of water and eliminate all high fructose containing sodas.
  • Check your blood work and see if you have any vitamin deficiencies. Talk your doctor if you have questions.

The information provided is for educational purposes. Any major change in lifestyle or nutrition should be discussed with your doctor.


Glen Carrigan is co-owner and operator of Freedom 4 Life Fitness with his wife Yvette. Glen & Yvette are dedicated and experienced personal trainers providing residents of Leawood, Overland Park KS, and greater Kansas City with an outstanding fitness experience.