By Dr. Mercola
Are you using artificial sweeteners and opting for low-cal "diet" foods in an effort to control of your weight?
If so, you may be surprised to learn that research has repeatedly shown that artificial no- or low-calorie sweeteners are anything but good news for weight loss... Contrary to popular belief, studies have found that artificial sweeteners such as aspartame can:
- Stimulate your appetite
- Increase carbohydrate cravings
- Stimulate fat storage and weight gain
The belief that artificially sweetened foods and beverages will help you lose weight is a carefully orchestrated deception. So if you are still opting for "diet" choices for this reason, you are being sorely misled. Ditto for diabetics, as recent research has shown aspartame also worsens insulin sensitivity.
The fact that these are still being promoted as "diet" flies in the face of any rational behavior. One wonders why the FTC doesn't come down like a ton of bricks on these companies for massively fraudulent marketing.
New Study Negates Weight Management Claims of Artificial Sweeteners
The featured study, published in the January 2013 issue of the journal Appetite2, was done by a Brazilian research team with the Faculty of Medicine of the Federal University do Rio Grande do Sul. Rats were fed plain yogurt sweetened with either aspartame, saccharin, or sugar, plus their regular rat chow, for 12 weeks.
"Results showed that addition of either saccharin or aspartame to yogurt resulted in increased weight gain compared to addition of sucrose, however total caloric intake was similar among groups," the researchers write.3
The reason for the similar calorie consumption between the groups was due to increased chow consumption by the rats given artificially sweetened yoghurt. This type of compensation has been found in previous studies4 as well, indicating that when your body gets a hit of sweet taste without the calories to go with it, it adversely affects your appetite control mechanisms, causing increased food cravings. The authors concluded that:
"Greater weight gain was promoted by the use of saccharin or aspartame, compared with sucrose, and this weight gain was unrelated to caloric intake. We speculate that a decrease in energy expenditure or increase in fluid retention might be involved."
You Actually Gain Weight by Using "Artificial Sweeteners
A 2010 scientific review published in the Yale Journal of Biology and Medicine (YJBM)5 discussed the neurobiology of sweet cravings and the unexpected effect of artificial sweeteners on appetite control. It cites several large scale prospective cohort studies that found positive correlations between artificial sweetener use and weight gain, which flies in the face of "conventional wisdom" to cut calories in order to lose weight. For example:
"The San Antonio Heart Study6 examined 3,682 adults over a seven- to eight-year period in the 1980s. When matched for initial body mass index (BMI), gender, ethnicity, and diet, drinkers of artificially sweetened beverages consistently had higher BMIs at the follow-up, with dose dependence on the amount of consumption. Average BMI gain was +1.01 kg/m2 for control and 1.78 kg/m2 for people in the third quartile for artificially sweetened beverage consumption.
The American Cancer Society study7 conducted in early 1980s included 78,694 women who were highly homogenous with regard to age, ethnicity, socioeconomic status, and lack of preexisting conditions. At one-year follow-up, 2.7 percent to 7.1 percent more regular artificial sweetener users gained weight compared to non-users matched by initial weight... Saccharin use was also associated with eight-year weight gain in 31,940 women from the Nurses' Health Study8 conducted in the 1970s."
Experiments have found that sweet taste, regardless of its caloric content, enhances your appetite. Aspartame has been found to have the most pronounced effect, but the same applies for other artificial sweeteners, such as acesulfame potassium and saccharin.
The reason why glucose or sucrose (table sugar) tends to lead to lower food consumption compared to non-caloric artificial sweeteners is because the calories contained in natural sweeteners trigger biological responses to keep your overall energy consumption constant. This was again evidenced in a study9 published last year, which concluded that:
"The results support the hypothesis that consuming non-caloric sweeteners may promote excessive intake and body weight gain by weakening a predictive relationship between sweet taste and the caloric consequences of eating."
In essence, real sugar allows your body to accurately determine that it has received enough calories, thereby activating satiety signaling. Without the calories, your appetite is activated by the sweet taste, but as your body keeps waiting for the calories to come, sensations of hunger remain.
"Human research must rely on subjective ratings and voluntary dietary control. Rodent models helped elucidate how artificial sweeteners contribute to energy balance. Rats conditioned with saccharin supplement had significantly elevated total energy intake and gained more weight with increased body adiposity compared to controls conditioned with glucose. Saccharin-conditioned rats also failed to curb their chow intake following a sweet pre-meal...
Increasing evidence suggests that artificial sweeteners do not activate the food reward pathways in the same fashion as natural sweeteners... Lastly, artificial sweeteners, precisely because they are sweet, encourage sugar craving and sugar dependence... Unsweetening the world's diet may be the key to reversing the obesity epidemic," the YJBM review states.10
That last statement is probably the most accurate conclusion there is. Americans in particular are addicted to the flavor sweet, which appears to trigger a complex set of biological systems, pathways, and mechanisms that in the end leads to excess weight gain whether that flavor comes loaded with calories or not.
Another Oft-Ignored Mechanism Driving Weight Gain from Artificial Sweeteners
Another reason for aspartame's potential to cause weight gain is because phenylalanine and aspartic acid – the two amino acids that make up 90 percent of aspartame -- are known to rapidly stimulate the release of insulin and leptin; two hormones that are intricately involved with satiety and fat storage. Insulin and leptin are also the primary hormones that regulate your metabolism.
So although you're not consuming calories in the form of sugar, aspartame can still raise your insulin and leptin levels. Elevated insulin and leptin levels, in turn, are two of the driving forces behind obesity, diabetes, and a number of our current chronic disease epidemics. Over time, if your body is exposed to too much leptin, it will become resistant to it, just as your body can become resistant to insulin, and once that happens, your body can no longer "hear" the hormonal messages instructing your body to stop eating, burn fat, and maintain good sensitivity to sweet tastes in your taste buds.
What happens then?
You remain hungry; you crave sweets, and your body stores more fat. Leptin-resistance also causes an increase in visceral fat, sending you on a vicious cycle of hunger, fat storage and an increased risk of heart disease, diabetes, metabolic syndrome and more.
Additionally, large doses of phenylalanine can lower important neurotransmitters like serotonin,11 which also influences satiety. Decreased serotonin levels reduce feelings of satiety, which can then lead to over-eating or binge eating. In the end, the research tells us that artificial sweeteners are nothing more than a pipe dream when it comes to being a dieter's aid, because contrary to what the marketing campaigns claim, low- or no-calorie artificial sweeteners are more likely to help you pack on the pounds than shed them.
What's the Answer for Stubborn Weight Gain?
The first thing you need to understand is that counting calories is typically useless for weight loss. This is because calories are NOT created equal, and will not have identical effects on your weight or health. And, as reviewed above, trying to fool your body with artificial sweeteners devoid of calories is not the answer. In fact, it will likely make matters worse.
Secondly, it's important to realize that the preferred fuel for your body is fat, not carbohydrates. Switching from a carb-based diet to a fat- and protein-based diet will help rebalance your body's chemistry, and a natural side effect of this is weight loss, and/or improved weight management once you're at an ideal weight. One explanation for this is that you don't really get fat from eating too much and exercising too little. Nor do you get fat from eating fat.
In fact, there's reason to believe that most people's health would benefit from having:
- As much as 60-70 percent healthful fats in their diet, and
- No more than one gram of protein per kilo of lean body mass or about 0.5 grams of protein per pound of lean body mass. (Can be increased by 25 percent if pregnant or aggressively exercising). To determine your lean body mass, calculate your body fat percentage and subtract that from 100. So if you are 20 percent body fat you would have 80 percent lean body mass. Then, multiply that times your current weight to get lean body mass in kilos or pounds
Dr. Richard Johnson's latest book, The Fat Switch, dispels many of the most pervasive myths relating to diet and obesity. He discovered the method that animals use to gain fat prior to times of food scarcity, which turned out to be a powerful adaptive benefit. His research showed that fructose activates a key enzyme, fructokinase, which in turn activates another enzyme that causes cells to accumulate fat. When this enzyme is blocked, fat cannot be stored in the cell.
Interestingly, this is the exact same "switch" animals use to fatten up in the fall and to burn fat during the winter. Fructose is the dietary ingredient that turns on this "switch," causing cells to accumulate fat, both in animals and in humans.
In essence, overeating and excess weight could be viewed as a symptom of the wrong proportion of macronutrients. You're simply not feeding your body the right fuel. It's not necessarily the result of eating too many calories, per se, but rather getting your calories from the wrong sources. In simple terms, when you consume too many sugars and carbs, you set off a cascade of chemical reactions in your body that makes you hungry and leaves you craving for sweets.
Even if you have the highest quality raw and organic foods, if you have a non-optimal combination with identical calories, you will likely gain weight. So listen to your body and if you are one of the two-thirds of people who are overweight, seriously consider radically reducing your carbs and replacing them with fibrous vegetables, lowering your protein levels to the quantity discussed above, and replacing those missing calories with healthy fats from coconut oil, olives, olive oil, avocado, pastured grass fed butter, and nuts. You can also try intermittent fasting, which will give you a radical jumpstart in your ability to normalize your weight.