Matt Metzgar

Artificial Sweeteners Don't Work

The title of this post may be common knowledge to some, but I am putting it out there for more notice.  I saw a guy at the grocery store today loading up his cart with six cases of diet soda.  Not coincidentally, he was overweight.

There is research going back 25 years showing that artificial sweeteners do not prevent weight gain.  A newer study from Yale shows that artificial sweeteners may increase weight via food reward.  Whatever the mechanism, they certainly do not contribute to weight loss and with a high probability contribute to weight gain.

Just drink water!

Sugar and Overeating

I came across another interesting open-access study about sugar.  From the abstract:

"We conclude that the chronic rather than acute sucrose intake reduces activity of the anorexigenic oxytocin system. These findings indicate that chronic consumption of sugar blunts activity of pathways that mediate satiety. We speculate that a reduction in central satiety signaling precipitated by regular intake of foods high in sugar may lead to generalized overeating."

Very interesting...

Long-Term Effects of Milk Consumption

There is a new open-access paper that shows the potential long-run negative effects of milk consumption, ranging from accelerated growth to early menarche.  The theory is that the high insulin response from cow's milk increases IGF-1 and accelerates development (which is not a good thing for a normal child).

Climbing the Charts

I just checked over on the main page at the International Journal of Food Sciences and Nutrition.  On the right, they have a column for "Most Read Articles", and there's my article, "Externalities from Grain Consumption: A Survey".

I think this is a great development, not just for me personally, but in terms of getting the word out that grains can have serious negative impacts.  The more that people know the better, so that they can make knowledgeable decisions about what to eat.

The Salt of the Land

I was alerted to a new review on salt and health markers.  It shows that in Caucasians, restricting salt barely has any effect.  It also slightly increases cholesterol and triglycerides.  Overall, they conclude that "we do not know if low salt diets improve or worsen health outcomes."  Based on a session I attended at the Ancestral Health Symposium, salt restriction only helps in the subset of people who are salt-sensitive anyways.

There's also evidence that moderate consumption of salt is actually a physiological need.  From a recent news article:

"Neurological research has demonstrated that animals in the laboratory "expressed an ingestive behavior designed to assure survival when threatened by sodium depletion." In other words, when salt levels fell dangerously low in animals, they sought out foods that were higher in salt until they re-established normal levels. Dr. McCarron and his colleagues posit that human beings engage in similar behaviors in order to maintain a normal sodium level.

In order to determine what that level might be, they evaluated 24-hour urinary sodium excretion from 19,151 individuals collected in 62 previously published surveys from 33 countries. They determined that adult human sodium intake ranges between 2,700 and 4,900 mg per day and concluded that "the likelihood that these diverse sources of data ... have defined the same range of sodium intake in adult humans purely by chance is exceedingly small."

They believe this data contradicts the idea that salt consumption has drastically increased in Western societies, since the range was the same across diverse cultures.

"We've been wired in our brains to consume salt within a very narrow range, to maintain our bodies' functions," said Dr. McCarron. "That range, at its very lowest limit, is 20 percent higher than what the government is telling us is the upper limit for the normal population. The average around the world ... is over 60 percent higher than what the government is telling us that we should consume."

Here's the full study(pdf).

Eating in the Absence of Hunger: Solutions III

Here is a third possible solution to eating in the absence of hunger, and I think the model is a pretty good one.  The full-text is available here.  The focus is on pediatric obesity, but I think the work could be extended to adults.

Just as it sounds, the model is about giving children freedom and trust so that they can self-regulate their food intake.  There are no restrictions on types of foods.  This table contrasts this approach versus traditional plans:

The study admits that more testing of this model is needed, but the theory looks correct to me.

Here's on paragraph I found particularly interesting:

"But can overweight individuals recognize hunger cues and stop eating when satiated? During a controlled intervention of 13 thin and 9 overweight adults, hunger ratings following overfeeding were reduced by 41% among thin individuals but remained unchanged for overweight individuals (46). In fact, when adults were overfed, hunger reduced significantly in the thin individuals and they reported higher satiety ratings. An explanation with empirical support is that overweight individuals both binge eat and diet/restrict food intake more frequently than thin individuals, which lead to disordered hunger and satiety cues (47). Restrained eaters overindulge in food after perceiving that they have broken dietary rules or have eaten a forbidden food (48,49). In the study when obese participants (who had earlier reported no impact of hunger or satiety cues on their food intake) were obligated to consciously focus on their hunger and satiety signals, they reported that they were able to detect these signals and modify their food intake (50)."

So even with overfeeding, the overweight still felt hungry!  It seems to me that even Paleo wouldn't be the solution here, because it is a primary malfunction of the hunger/satiety mechanisms that appears to be separate from the type of food.

Eating in the Absence of Hunger: Solutions II

Here's another possible solution to eating in the absence of hunger, though I haven't had time to check it out.  I will just repost the abstract:

"It is hypothesised that eating is regulated when eating pleasure fulfills (and thus extinguishes) the desire to eat and that eating pleasure is maximised when eating is prompted by an Empty Hollow Sensation (EHS). Absent, unrecognised, misinterpreted or false hunger sensations may account for non-regulated eating in many so-called normal eaters, not only in anorexic or obese people. As a regime in which the EHS is present before most meals, the EHS Meal Pattern (EHSMP) is suggested. Existing evidence to support its efficacy is reviewed. Obesity, diabetes and heart disease are among a range of conditions associated with excessive caloric intake owing to poorly regulated eating. If upheld, the EHSMP could assist people to maintain their own well being and could help to prevent and treat some of the major scourges of Western society."

Eating in the Absence of Hunger: Solutions

I saw a new study that I'm trying to get the full-text of.  It tested two treatments to reduce binge eating and eating in the absence of hunger in overweight children.  One of the treatments, related to food cues, was successful in reducing both binge eating and eating in the absence of hunger.

This is the way I predict the research continue going.  Instead of telling people to avoid all types of energy-dense foods, the focus will be on getting people to properly regulate their eating and avoid eating when not hungry.

The Food Reward Arms Race

A few commenters mentioned the food reward theory in previous posts.  One thing that should be pointed out is that rewarding food is not going away anytime soon (barring regulation), and that simple logic would predict that it will continue to increase.

Competition between restaurants and food manufacturers is all about gaining customers and profits.  If one company can change their recipes and gain business, then other companies will surely try to respond with an enhanced recipe of their own.

This sets up a game theory situation like we talk about in economics.  Restaurants and food manufacturers effectively engage in an endless arms race of trying to create more rewarding food.  Of course, this may not be beneficial for consumers as this food can be semi-addicting.

In fact, a new paper by Andrea Garber and Robert Lustig asks that question in the paper's title, "Is Fast Food Addictive?"  I would say that even if fast food isn't addictive yet, it most likely will end up that way as restaurants look to keep pace. 

Economic logic strongly predicts this will be the outcome.

Evolutionary Origins of Anorexia

I came across this fantastic paper that looks at anorexia from an evolutionary perspective.  The authors hypothesize that initial bouts of calorie restriction (aka dieting) set the stage for later anorexia.

From the full-text:

"The goal of the starvation response is to conserve energy, delay growth processes, preserve cellular levels of ATP (in part, by increasing the efficiency of energy metabolism) and minimize oxidative damage. This response is essential for survival during times of food/nutrient shortage and is, consequently, highly conserved through evolution."

"The net result of deficits in the starvation response is that patients fail to exhibit normal appetite or to properly regulate their response to fasting and fuel shortage. This leads to a vicious cycle. Thus, a bias toward denial of food leads to a reduction in calorie consumption, and weight loss. As weight loss proceeds, production of ancillary signals to initiate feeding, such as IGF-1 and dopamine (controlled by FOXO), is diminished and the starvation response is further activated. However, because this response is defective in AN (anorexia nervosa), counterregulatory (orexigenic) mechanisms are ineffectual, and a persistent catabolic state develops, much like anorexia associated with cancer or infectious diseases. The fact that some anorexic patients literally starve themselves to death attests to the failure ofevolutionarily conserved survival strategies in AN. "

"Efforts to treat AN solely with behavioral approaches may have had limited success because they target the sequelae of the disorder rather than the etiology, and rely on ‘will power’ when the real culprit may be a metabolic defect akin to the situation in diabetes mellitus."

They also mention Ancel Keys and his starvation experiment in the article as well. 

Overall, they show that anorexia could be an evolutionary mechanism gone haywire, as is the case for other modern maladies.

The pdf is on the web if you search for it.