Saturday, March 8, 2014

Diet News Bundle I: Sugar, Protein and the Diet Debacle

Dietary news. It changes every now and then.

But after reading many dietary advice and opinions, about the only thing I can believe is: Sugar has very little nutritional value, and may have very bad effects on our health.

You do not have to believe me of course. I am not an expert. And I haven't kept track of all the news and information that I have sieved through to arrive at this partial conclusion (Note: I wrote, "may have very bad effects".) You should read about sugar for yourself and make up your own minds.

The last article actually provides some sort of scientific explanation that makes a lot of sense (to me). BUT... you should decide for yourself.

This first article is on Sugar:

Cut sugar consumption by half: WHO

March 6 2014

LONDON — Just try sugar-coating this: The World Health Organisation says your daily sugar intake should be just 5 per cent of your total calories - half of what the agency previously recommended, according to new draft guidelines published yesterday (March 5).

After a review of about 9,000 studies, WHO’s expert panel says dropping sugar intake to that level will combat obesity and cavities. That includes sugars added to foods and those present in honey, syrups and fruit juices, but not those occurring naturally in fruits.

Dr Francesco Branca, WHO’s director for nutrition, conceded the new target was somewhat aspirational.

“We should aim for 5 per cent if we can ... but 10 per cent is more realistic,” he said in a news conference.

Americans and others in the West eat a lot more sugar than that: Their average sugar intake would have to drop by two-thirds to meet WHO’s suggested limit.

WHO’s new guidelines have been published online and the agency is inviting the public to comment via its website until the end of March.

Many doctors applauded the United Nations agency’s attempt to limit the global sweet tooth.

“The less sugar you’re eating, the better,” said Dr Robert Lustig, a professor of paediatrics at the University of California and author of a book about the dangers of sugar. “If the sugar threshold is lowered, I think breakfast cereal is going to have a really hard time justifying its existence,” he said, referring to sweetened cereals often targeted to children.

When WHO last revised its sugar guidelines more than a decade ago, it recommended sugar should be less than 10 per cent of daily calories. The United States sugar industry was so incensed it lobbied Congress to threaten to withdraw millions of dollars in funding to WHO. A contentious reference to the sugar limit was removed from a global diet strategy, but the recommendation passed.

[Note: the Sugar Lobby blackmailed the WHO to soften their stance. Understandable? Yes. Commercial interests trumps Health issues? Sounds like it to me. Business blackmails Science? That's what it looks like to me.]

Dr Lustig said WHO’s new guidelines could alter the food environment by forcing manufacturers to rethink how they’re using sugar in processed foods like bread, soups, pasta sauces and even salad dressings. He called the amount of sugar in processed food an “absolute, unmitigated disaster”.
WHO’s expert group found high sugar consumption is strongly linked to obesity and tooth decay. It noted that heavy people have a higher risk of chronic diseases, responsible for more than 60 per cent of global deaths. Dental care costs up to 10 per cent of health budgets in Western countries and cause significant problems in the developing world.

WHO warned many of the sugars eaten today are hidden in processed foods, pointing out that one tablespoon of ketchup contains about one teaspoon of sugar and that for some people, including children, drinking a single can of sweetened soda would already exceed their daily sugar limit.

There is no universally agreed consensus on how much sugar is too much.

The American Heart Association advises limiting sugar to about 8 per cent of your diet, or six teaspoons a day for women and nine for men. A study led by the US Centres for Disease Control and Prevention published last month found too much sugar can raise the chances of fatal heart problems. Researchers found the average American gets about 15 per cent of their calories from sugar, similar to other Western nations.

New nutrition labels proposed in the US will also require food manufacturers to list any added sugars, plus a more prominent calorie count.

Earlier this week, Britain’s chief medical officer, Dr Sally Davies, said she thought sugar might be addictive and that the government should consider introducing a sugar tax to curb bulging waistlines. The United Kingdom has one of the fattest populations in Western Europe.

“We have a generation of children who, because they’re overweight ... may not live as long as my generation,” she told a health committee. “They will be the first generation that lives less and that is of great concern.” AP


[The second article is on animal protein (meat, generally), and the need to restrict the consumption of such. ]

Diet rich in animal protein could be as bad as smoking: US study

March 7 2014

LONDON — A diet rich in meat, eggs, milk and cheese could be as harmful to health as smoking, according to a study released this week.

The study, which involved 6,381 people aged 50 and above who were surveyed in the United States, found that high levels of dietary animal protein in people under 65 was linked to a four-fold increase in their risk of death from cancer or diabetes, and almost double the risk of dying from any cause over an 18-year period.

These risks were cut when protein came from plant sources such as beans, though cancer risk was still three times as high in middle-aged people who ate a protein-rich diet.

Conversely, the study also found that animal-protein-rich diets in those above 65 cut the risk of death from any cause by 28 per cent, and reduced cancer deaths by 60 per cent.

The results were published in the journal Cell Metabolism.

[Note that the study involved people aged 50 and above. So if you are below 50, maybe these findings don't apply to you? And also for those above 65, animal-protein-rich diet is actually better. So... between the age of 50 and 65, you need to eat tofu?

The report does not explain why the study restricted the subjects to those above 50. There may be logistical reasons, or theoretical reasons, or the findings may not be applicable to the general, or younger (below 50 yrs) population.]

Dr Valter Longo, Director of the Longevity Institute at the University of Southern California, said that on the basis of the study and previous work, people should restrict themselves to no more than 0.8g of protein a day for every kilogramme of body weight — equivalent to 48g for a 60kg person.

[In case you are wondering what 50g looks like, a hamburger from MacDonald's - i.e. the smallest burger - would have a beef patty of about 70 gm. Assuming a Big Mac has two standard patties, that would be about 140 gm. A Quarter pounder would have about 110 gm of beef. Assuming that the beef patty is 100% beef, or close to 100%. And yes, I do believe "pink slime" would be considered animal-protein. 

A proper steak house steak could vary in serving size between 150 gm to 220gm for a single serving to multiples of that for double or triple servings.

A single chicken wing may well bust the 50gm limit for a 60 kg person.]

“People need to switch to a diet where only around 9 or 10 per cent of their calories come from protein and the ideal sources are plant-based,” Dr Longo told the Guardian. “If we are right, you are looking at an incredible effect that, in general, is about as bad as smoking.”

However, nutrition experts have cautioned that it is too early to draw firm conclusions from the research.

The apparently harmful effects of a high-protein diet might be down to one or more other substances in meat, or driven by lifestyle factors that are more common in regular red meat eaters versus vegetarians.

Said Dr Peter Emery, Head of Nutrition and Dietetics at King’s College London: “I would urge general caution over observational studies, and particularly when looking at diet, given the difficulties of disentangling one nutrient or dietary component from another. You can get an association that might have some causal linkage or might not.” 


[The tone of the above study seems to be a little tentative... And certainly the meat industry (and the fast food industry) would be cautious about the findings of such a study. Well, the findings for this is controversial and contradictory as well (different results for those over 65 and those below 65). So this is one more data point, but don't change your diet and lifestyle just because of ONE study. The next article seems more comprehensive.]

May 29, 2012

Robert H. Lustig: The Diet Debacle

SAN FRANCISCO - Two seemingly benign nutritional maxims are at the root of all dietary evil: A calorie is a calorie, and You are what you eat. Both ideas are now so entrenched in public consciousness that they have become virtually unassailable. As a result, the food industry, aided and abetted by ostensibly well-meaning scientists and politicians, has afflicted humankind with the plague of chronic metabolic disease, which threatens to bankrupt health care worldwide.

The United States currently spends US$147 billion on obesity-related health care annually. Previously, one could have argued that these were affluent countries' diseases, but the United Nations announced last year that chronic metabolic disease (including diabetes, heart disease, cancer, and dementia) is a bigger threat to the developing world than is infectious disease, including HIV.

These two nutritional maxims give credence to the food industry's self-serving corollaries: If a calorie is a calorie, then any food can be part of a balanced diet; and, if we are what we eat, then everyone chooses what they eat. Again, both are misleading.

If one's weight really is a matter of personal responsibility, how can we explain toddler obesity? Indeed, the US has an obesity epidemic in six-month-olds. They don't diet or exercise. Conversely, up to 40 per cent of normal-weight people have chronic metabolic disease. Something else is going on.

[Video on "What if we're wrong about Diabetes"]

Consider the following diets: Atkins (all fat and no carbohydrates); traditional Japanese (all carbohydrates and little fat); and Ornish (even less fat and carbohydrates with lots of fiber). All three help to maintain, and in some cases even improve, metabolic health, because the liver has to deal with only one energy source at a time.

That is how human bodies are designed to metabolise food. Our hunter ancestors ate fat, which was transported to the liver and broken down by the lipolytic pathway to deliver fatty acids to the mitochondria (the subcellular structures that burn food to create energy). On the occasion of a big kill, any excess dietary fatty acids were packaged into low-density lipoproteins and transported out of the liver to be stored in peripheral fat tissue. As a result, our forebears' livers stayed healthy.

Meanwhile, our gatherer ancestors ate carbohydrates (polymers of glucose), which was also transported to the liver, via the glycolytic pathway, and broken down for energy. Any excess glucose stimulated the pancreas to release insulin, which transported glucose into peripheral fat tissue, and which also caused the liver to store glucose as glycogen (liver starch). So their livers also stayed healthy.

And nature did its part by supplying all naturally occurring foodstuffs with either fat or carbohydrate as the energy source, not both. Even fatty fruits - coconut, olives, avocados - are low in carbohydrate.

Our metabolisms started to malfunction when humans began consuming fat and carbohydrates at the same meal. The liver mitochondria could not keep up with the energy onslaught, and had no choice but to employ a little-used escape valve called 'de novo lipogenesis' (new fat-making) to turn excess energy substrate into liver fat.

Liver fat mucks up the workings of the liver. It is the root cause of the phenomenon known as 'insulin resistance' and the primary process that drives chronic metabolic disease. In other words, neither fat nor carbohydrates are problematic - until they are combined. The food industry does precisely that, mixing more of both into the Western diet for palatability and shelf life, thereby intensifying insulin resistance and chronic metabolic disease.

[So that is why fries, which are carbo fried in fat is both addictive, and bad for our health.]

But there is one exception to this formulation: sugar. Sucrose and high-fructose corn syrup are comprised of one molecule of glucose (not especially sweet) and one molecule of fructose (very sweet). While glucose is metabolised by the glycolytic pathway, fructose is metabolised by the lipolytic pathway, and is not insulin-regulated. Thus, when sugar is ingested in excess, the liver mitochondria are so overwhelmed that they have no choice but to build liver fat. Today, 33 per cent of Americans have a fatty liver, which causes chronic metabolic disease.

Prior to 1900, Americans consumed less than 30 grams of sugar per day, or about 6 per cent of total calories. In 1977, it was 75 grams/day, and in 1994, up to 110 grams/day. Currently, adolescents average 150 grams/day (roughly 30 per cent of total calories) - a five-fold increase in one century, and a two-fold increase in a generation. In the past 50 years, consumption of sugar has also doubled worldwide. Worse yet, other than the ephemeral pleasure that it provides, there is not a single biochemical process that requires dietary fructose; it is a vestigial nutrient, left over from the evolutionary differentiation between plants and animals.

It is therefore clear that a calorie is not a calorie. Fats, carbohydrates, fructose, and glucose are all metabolised differently in the body. Furthermore, you are what you do with what you eat. Combining fat and carbohydrate places high demands on the metabolic process. And adding sugar is particularly egregious.

Indeed, while food companies would have you believe that sugar can be part of a balanced diet, the bottom line is that they have created an unbalanced one. Of the 600,000 food items available in the US, 80 per cent are laced with added sugar. People cannot be held responsible for what they put in their mouths when their choices have been co-opted.

[Bottom line, cut sugar out of your diet.]

And this brings us back to those obese toddlers. The fructose content of a soft drink is 5.3 per cent. Of course, many parents might refuse to give soft drinks to their children, but the fructose content of soy formula is 5.1 per cent, and 6 per cent for juice.

We have a long way to go to debunk dangerous nutritional dogmas. Until we do, we will make little headway in reversing an imminent medical and economic disaster.

Robert Lustig is Professor of Pediatrics in the Division of Endocrinology, Director of the Weight Assessment for Teen and Child Health Program, and a member of the Institute for Health Policy Studies at the University of California, San Francisco.

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