Diet research, stuck in the stone age.
A current diet study making headlines purportedly asked, and answered this question: Which is better for weight loss and improving cardiac risk, a low-fat or a low-carb diet? writes Dr David Katz in the Huffington Post. The following edited summary is reproduced with his permission.
But the study didn't even really ask this question says Katz. Allegedly, the researchers compared a low-fat to a low-carb diet. But in fact, they compared a diet that allowed up to 30 percent of calories from fat to a diet that allowed up to 40 grams of daily carbohydrate.
The baseline diets were, reportedly, roughly 2,000 calories per day on average among the nearly 140 obese (i.e., BMI > 30) study participants. (This is a bit suspect, since calorie intake would be predicted to be higher in obese adults.) That means the allegedly low-fat diet assignment allowed up to 600 calories per day from fat, while the low-carb assignment allowed only about one-quarter that much carbohydrate, 160 calories. The baseline fat intake of the participants in the low-fat assignment was just over 35 percent of calories, so this was, essentially, a diet intervention that didn't intervene much with their diets.
In contrast, baseline carbohydrate intake was 240 grams per day, so while fat intake was "trimmed" 5 percent, carbohydrate intake in that assignment was slashed 75 percent. This might have been billed "a study to compare a really big change from baseline diet to a really small change from baseline diet”.
That would be bad and biased enough if the researchers had made any attempt to compare comparably good, or comparably bad versions of the two diets; but they did not. The "low-fat" diet was, for starters, not much lower in fat than the typical American diet, which as we all know -- is basically crap.
Shockingly, the fiber intake was virtually identical, at about 15 to 16 grams per day, in both groups throughout the study. You cannot possibly eat any variant on the theme of "good" low-fat, mostly plant-based eating and fix the fiber intake at that pitiful level. The only way to do that is to combine modestly low fat with preferentially crummy foods made mostly from refined starches and added sugars. The study did not provide this level of detail about the diets, but it's clear that the low fat diet was (A) not low fat; and (B) rather crummy. So another title option was: "a comparison of the best low-carb diet to the worst low-fat diet we could come up with."
And finally, the low-carb diet, since it was actually low-carb, obviously was much more restrictive than the low-fat diet, which wasn't actually low-fat. That had the predictable result: those on the low-carb assignment took in many fewer calories (this information in summarized in Table 2 in the article). Over the first several months of the study, when everyone was probably on their best behavior, the low-carb group took in about 200 fewer calories per day. All the way out at the 12-month mark, when folks were falling off the wagon, the low-carb assignees were still taking in nearly 100 fewer calories per day. And so, the results were a foregone conclusion. Over the span of a year, obese people who ate less, lost more weight. And those who lost more weight had more improvement in their cardiac risk measures -- which were mostly a mess in the first place due to obesity. Ta-da!
[The study] is both prehistoric and propaganda. It was a comparison of a quite restricted, lower-calorie, low-fiber diet; to a less restricted, higher calorie, equally low-fiber diet. The first worked better for weight loss. Ignored in the mix? Was the diet sustainable when the intervention ended? Could families join in? Would the diet reliably improve health and prevent disease across a lifespan?
And here he comments on identical twin brothers Van Tulleken who did their own diet comparison for a month. Chris cut fat. Xand cut carbs. Both brothers agreed that Chris “won.” For the span of a month, cutting fat produced better overall results in these identical twin doctors. But that’s not the point. You can read more HERE.
Food addiction? Unlikely. Eating addiction is more likely.
People can become addicted to eating for its own sake but not to consuming specific foods such as those high in sugar or fat, research published in Neuroscience and Biobehavioral Reviews suggests. An international team of scientists has found no strong evidence for people being addicted to the chemical substances in certain foods. The brain does not respond to nutrients in the same way as it does to addictive drugs such as heroin or cocaine, the researchers say. Instead, people can develop a psychological compulsion to eat, driven by the positive feelings that the brain associates with eating. This is a behavioural disorder and could be categorised alongside conditions such as gambling addiction, say scientists at the University of Edinburgh. They add that the focus on tackling the problem of obesity should be moved from food itself towards the individual's relationship with eating.
“…there is very little evidence to indicate that humans can develop a “Glucose / Sucrose / Fructose Use Disorder” as a diagnosis within the DSM-5 category Substance Use Disorders. We do, however, view both rodent and human data as consistent with the existence of addictive eating behavior,” they conclude. Dr John Menzies, Research Fellow in the University of Edinburgh's Centre for Integrative Physiology, said: “People try to find rational explanations for being over-weight and it is easy to blame food. Certain individuals do have an addictive-like relationship with particular foods and they can over-eat despite knowing the risks to their health. More avenues for treatment may open up if we think about this condition as a behavioural addiction rather than a substance-based addiction.”
Professor Suzanne Dickson, of the University of Gothenburg and co-ordinator of the NeuroFAST project, added: “There has been a major debate over whether sugar is addictive. There is currently very little evidence to support the idea that any ingredient, food item, additive or combination of ingredients has addictive properties.”
Chromium and blood glucose – does it make a difference?
Chromium is an essential nutrient (trace element) that’s vital for good health. It may only play a bit part alongside the dietary biggies (iron, calcium or zinc), but that bit part is a key player in how our bodies metabolise carbohydrate, fat and protein. It has been extensively researched over the years regarding its role in glucose metabolism. The most recent study which analyses nearly three decades of data on the effect of chromium supplementation on blood glucose concludes that chromium supplements are not effective at lowering fasting blood glucose in anybody – neither healthy individuals, nor people with diabetes.
Where do we get it? Eating a varied, balanced diet will give us all we need. It is widely available in the food supply and we only need a tiny or trace amount (ranging from about 25–45micrograms per day). The best source is brewer's yeast, but many people don’t go there because it can make you feel bloated and even cause nausea. More popular choices include: bran-based breakfast cereals, wholegrain breads and cereals, egg yolk, cheese, yeast extract like Vegemite, fruits such as apples, oranges and pineapple, vegetables such as broccoli, mushrooms, potatoes with their skin on, tomatoes, liver, kidney and lean meat, peanuts, oysters and some spices like pepper and chilli.
This is an edited extract from the Ultimate Guide to Sugars and Sweeteners reproduced courtesy The Experiment Publishing (New York).
Inulin is an ingredient you will see increasingly often on food labels, as it is being used in conjunction with high-intensity sweeteners to enhance flavor and replace sugar and other nutritive sweeteners in sugar-free, sugar-reduced, or “diet” products such as chocolate, baked goods, breakfast cereals, cereal bars, yogurt, and beverages. We have also spotted it in organic stevia sweeteners, where it provides both bulk and a prebiotic bonus; although we can’t digest it, the healthy bacteria (like Bifidobacteria and Lactobacilli) in our large intestine just lap it up.
It’s not a sugar or sweetener per se; it’s a fructan, a type of soluble dietary fiber found in agave, artichokes, asparagus, bananas, carrots, chicory root, garlic, Jerusalem artichokes, jicama, leeks, onions, wheat, and yacon. The food industry’s main sources of inulin are chicory root and Jerusalem artichoke.
In simple terms, a fructan is a chain of fructose molecules joined together. Short-chain fructans are known as fructooligosaccharides (also called oligofructose) and are about 30 percent as sweet as granulated sugar (sucrose); longer-chain fructans are known as inulins and are only about 10 percent as sweet as granulated sugar.
Although it shares some of sugar’s physical characteristics, such as providing bulk, it is not sufficiently sweet to replace brown or white sugar in recipes on a cup-for-cup basis. If you are tempted to use it in your baking, try it out first in a recipe that has been developed and tested with it (and that shows you a photograph of the end product), rather than substituting it for sugar in one of your favorites. It is not suitable for people who are following a low-FODMAP diet.
1 October 2014
Diet research, stuck in the stone age.
Posted by GI Group at 1:36 am