Diet planning as conversation, not monologue

Implementing shared decision making in nutrition clinical practice: A theory-based approach and feasibility study
Original source: Implementation Science 2008, 3:48
Authors: Sophie Desroches (corresponding author), Sylvie Tapp, Marie-Pierre Gagnon, and France Legare
Publication date: 5 November 2008
DOI (digital document ID): 10.1186/1748-5908-3-48
Requires subscription? No
Publicly-available abstract: Yes

Synopsis:
Shared decision making is one of several methods that a health professional can use to help us change our eating habits to better control diabetes and other chronic illnesses. The investigators are looking primarily at dietary approaches to lower cholesterol levels.

The traditional low-fat/low-saturated fat strategy to lower cholesterol is perceived as restrictive, leading to a tendency for people to either "cheat" or to not follow the diet at all. Recently, a number of different dietary approaches have been shown effective in lowering cholesterol -- but the variety, added to the many diet systems discussed in the popular media, can leave the general public confused. Shared decision is a method in which the dietician works collaboratively with the patient, taking into account his cultural and financial perferences, to create a healthy diet that the patient is willing to follow. The process includes explaining the best evidence of the risks and benefits of different dietary models, and explicitly states that the method does include some uncertainties.

The authors of this investigation found no formal studies supporting the use and training of a shared decision making approach using evidence-based practice, and note that some dieticians have reported difficulty in suggesting and implementing this approach.

In this paper they propose a study to learn how shared decision-making is currently used in the field of nutritional consultation, to assess dieticians' intention to adopt two specific behaviors related to shared decision making using the Theory of Planned Behavior, and to learn what the obstacles are to dieticians adopting this approach. Their proposed protocol includes the education of dieticians, the introduction of the Theory of Planned Behavior, focus group discussions in which the dieticians' views and issues are discussed, and audiotaped observation of the dieticians' interactions with patients.

The proposed research project is expected to provide preliminary data about the adoption of shared decision making by dieticians and their patients, look at dieticians' beliefs regarding their intention to adopt shared decision making behaviors and comparing their actions to their intentions, and develop questionnaires to measure this information. The researchers hope that the results generated by the proposed research project will help improve the rate at which dieticians adopt a shared decision-making approach.

Reliability:
The initial study is intended to cover only 40 dieticians, but this is considered mostly as a focus group from which the parameters of a larger study can be planned.

Practical Applications:
The end goal of this research is to increase the adoption of shared decision making in the field of nutritional consulation. Having our dieticians engage us actively, and pay attention to our input, will help us find diets we can -- and will -- live with.

This synopsis was based on the entire article.

How does your body-fat distribution affect your risk of death?

General and Abdominal Adiposity and Risk of Death in Europe
Original source: New England Journal of Medicine Volume 359:2105-2120 November 13, 2008 Number 20
Authors: T. Pischon, H. Boeing, K. Hoffmann, M. Bergmann, M.B. Schulze, K. Overvad, Y.T. van der Schouw, E. Spencer, K.G.M. Moons, A. Tjønneland, J. Halkjaer, M.K. Jensen, J. Stegger, F. Clavel-Chapelon, M.-C. Boutron-Ruault, V. Chajes, J. Linseisen, R. Kaaks, A. Trichopoulou, D. Trichopoulos, C. Bamia, Ph.D., S. Sieri, D. Palli, R. Tumino, P. Vineis, S. Panico, P.H.M. Peeters, A.M. May, H.B. Bueno-de-Mesquita, F.J.B. van Duijnhoven, G. Hallmans, L. Weinehall, J. Manjer, B. Hedblad, E. Lund, A. Agudo, L. Arriola, A. Barricarte, C. Navarro, C. Martinez, J.R. Quirós, T. Key, D.Phil., S. Bingham, K.T. Khaw, P. Boffetta, M. Jenab, P. Ferrari, and E. Riboli
Publication date: November 13, 2008
DOI (digital document ID): (unavailable)
Requires subscription? No
Publicly-available abstract: Yes

Synopsis:
This article addresses the question of whether the risks of obesity are related to the distribution of body fat, rather than the existence of fat excess body weight alone.

The investigators examined Body Mass Index (BMI), waist circumference, and waist-to-hip ratio with the risk of death among 359,387 participants from nine countries over a period of almost ten years. The results were analyzed based on age at recruitment into the study, location at which they were entered into the study, height, educational level, whether or not the subject smoked, how much alcohol the person drank, and how physically active the person was.

The 1% of respondents with the highest and lowest energy intakes relative to estimated energy requirements were excluded from the study, as were respondents with a history of cancer, heart disease, or stroke.

"Normal" weight was considered to range from BMI 18.5 to BMI 25.0

The lowest risks of death based on BMI were at 25.3 for men and 24.3 for women. (This corresponds to the borderline between "normal weight" and "overweight".) After adjusting for this, absolute waist size and large waist-to-hip ratio were associated with greater risk of death. These last two correlations were stronger for people with lower BMI than for those with higher BMI, and stronger for men than for women.

One possible reason for the gender-related difference may be that overweight men tend to carry more fat in their midsections (visceral-fat) than equally-overweight women. This is important because visceral-fat tissue secretes a number of chemicals (lipokines) that can cause or exacerbate a number of chronic diseases.

Interestingly, it was found that the reasons for increased risk of death changed depending on waist measurement: those people who died and who were simply overweight or obese had more deaths from circulatory issues than from other causes, whereas those who had more abdominal obesity tended to die from respiratory issues rather than from other causes. (This may be a confounding issue, related to the observation that smokers tend to have more abdominal fat than non-smokers of similar BMI, and that smokers have higher risk of dying from respiratory system issues. The authors note that there is a known association between abdominal adiposity and chronic bronchitis, but do not state if this is a smoking-related association or not.)

The researchers conclude that these data suggest that both high body weight and abdominal fat are associated with higher risk of death, and support the use of waist circumference and or waist-to-hip ratio in addition to BMI in assessing the risk of death.

Reliability:
This study followed a large number of people for a relatively long period of time, making the study population relatively reliable; however, high BMI is not always related to adiposity. Body-builders, as a noted example, can have BMI in the obese range, but body fat measurement by either bioelectrical measurement or water immersion will indicate extremely low body fat percentages. On the other hand, these people generally have waist measurements and waist-to-hip ratios that are significantly smaller than people of the same body mass index, but with greater percentages of body fat. They also tend to have higher metabolic rates, making them more likely to place in the highest caloric intake per kilogram of body mass; some people who fit in this category were probably excluded from the study for that reason.

Another consideration, noted briefly by the investigators, is that there are a number of chronic diseases that were not excluded from the study. Some of these (such as Type 2 diabetes) affect, or are affected by, body weight and weight distribution. These could also affect the relative risks of death of the population observed.

Practical Applications:
The use of waist measurements and waist-to-hip ratios, in conjunction with BMI, can assist doctors and public health professionals in assessing individual and community health risks.

The authors' Figure 2, representing relative risk based on waist circumference and waist-to-hip ratio, shows a standardized risk of 1.0 for men at approximately 93 cm (about 36"), 0.94 waist-to-hip ratio (36" waist corresponding to about 39" hip), and for women at approximately 77 cm (about 30") waist size, 0.79 waist-to-hip ratio (30" waist corresponding to about 38" the hip). These measurements are lower than the standards currently used for determination of risk (102 cm/40" for men, 88cm/35" for women). Interestingly, these measurements correspond to the largest "standard" reference clothing sizes (men's pants to jacket size 42, women to U.S. Misses size 16/European size 42) as expressed in the home-sewing pattern industry, or "true-to-size" in the ready-to-wear industry.

This suggests that an average person should be able to determine his or her risk based on off-the-rack clothing size.

For further reading:
Home-sewing pattern measurements:

• Simplicity Patterns (United States):
  
  • US measurements
  • European measurements


• Burda Patterns (Germany):
  
  • US and European measurements

This synopsis was based on the complete article.

Iron-rich blood and metabolic syndrome

Hyperferritinemia Is Associated with Insulin Resistance and Fatty Liver in Patients without Iron Overload
Original source: PLoS ONE 3(10): e3547
Authors: Robert Brudevold (corresponding author), Torstein Hole, Jens Hammerstrøm
Publication date: October 28, 2008
DOI (digital document ID): 10.1371/journal.pone.0003547
Requires subscription? No
Publicly-available abstract: Yes

Synopsis:
Over the past ten years, the investigators have seen a rise in patients with hyperferritinemia (high blood ferritin) -- excess iron in the blood. A certain amount of this is to be expected given the increasing awareness of hereditary hemochromatosis -- a genetic condition in which the blood retains an overload of iron. High blood ferritin is also seen in cases of inflammation and in cancer. Over the same period, there has been an increase in patients whose high ferritin levels cannot be explained by these conditions. Most of these patients are overweight, middle-aged men.

Previous research suggested links between elevated ferritin levels and non-alcoholic fatty liver disease (NASH -- in technical terms, non-alcoholic steatohepatitis), and between high ferritin and insulin resistance. Both NASH and insulin resistance are often seen in patients with metabolic syndrome. The authors chose to examine this possible link in more detail.

They examined forty consecutive patients referred to them for hyperferritinemia. After examination, 34 patients remained with unexplained hyperferritinemia -- 1 woman and 33 men. Fasting blood samples were taken and analyzed for iron, liver enzymes, c-reactive protein (a marker for inflammation), and c-peptide (a marker for insulin production). Liver biopsies were obtained for 29 of the patients, and liver iron stores were assessed for 16 of them.

The majority of the patients had either markers for metabolic syndrome, or could be clinically diagnosed as having metabolic syndrome, showing increased body mass index, elevated diastolic blood pressure, and insulin resistance. Nineteen of the 29 patients biopsied had steatosis (fatty livers). Only four patients showed increased levels of iron in their livers -- of which two could be explained by alcohol consumption. Ferritin levels were higher in subjects with insulin resistance than in those without.

Fourteen of 16 patients normalized ferritin levels after phlebotomy (removal of an amount of blood -- a standard medical procedure for persons with hemochromatosis), but after a while, their ferritin levels rose again. Those who changed lifestyle (diet and exercise) -- first-line therapy for patients with metabolic syndrome -- had stabler ferritin levels. Since NASH is often seen in obese patients and in patients with metabolic syndrome, this evidence supports the theory associating NASH with increased ferritin levels.

These observations suggest that fatty livers and insulin resistance, but not increased iron storage in the liver, may be frequently seen in patients referred to specialists because of high ferritin levels. The authors conclude that ferritin levels seem to be higher in people with insulin resistance and suggest that high ferritin levels are markers of metabolic syndrome with NASH and insulin resistance, rather than iron overload.

Reliability:
There were very few subjects examined in this study, and no indication of how common this complaint is within the population affected by insulin resistance and/or metabolic syndrome. Because of this, there is a possibility of skewed data.

The tests support previous research, adding information to the existing body of knowledge and suggesting directions for further research.

The authors are associated with accredited medical institutions and the article is published in a peer-reviewed journal.

Practical Applications:
Understanding the entire extent of physiological changes associated with metabolic syndrome can help doctors and pharmacists better understand both metabolic syndrome in general and how best to treat the individual patients.

While the population studied is small, it supports our understanding that lifestyle management -- maintenance of a stable, healthy weight through diet and exercise -- is of vital importance for maintaining or improving our overall health.

Ethics note: All patients gave oral consent to the examination program and to the use of clinical data for research purposes.

This synopsis was based on the entire article.

Mediterranean Diets: low-carb versus low glycemic load

Spanish Ketogenic Mediterranean diet: a healthy cardiovascular diet for weight loss
Original source: Nutrition Journal 2008, 7:30
Authors: Joaquin Perez-Guisado (corresponding author), Andres Munoz-Serrano, and Angeles Alonso-Moraga
Publication date: 26 October 2008
DOI (digital document ID): 10.1186/1475-2891-7-30
Requires subscription? No
Publicly-available abstract: Yes

Enhancement of a modified Mediterranean-style, low glycemic load diet with specific phytochemicals improves cardiometabolic risk factors in subjects with metabolic syndrome and hypercholesterolemia in a randomized trial
Original source: Nutrition & Metabolism 2008, 5:29
Authors: Robert H Lerman (corresponding author), Deanna M Minich, Gary Darland, Joseph J Lamb, Barbara Schiltz, John G Babish, Jeffrey S Bland, and Matthew L Tripp
Publication date: 4 November 2008
DOI (digital document ID): 10.1186/1743-7075-5-29
Requires subscription? No
Publicly-available abstract: Yes

Synopsis:
Both of these studies looked at variants of the Mediterranean Diet, followed over a period of 12 weeks (three months). The Spanish study emphasized the use of virgin olive oil as the primary source of dietary fat, green vegetables and salads as the primary source of carbohydrates, and fish as a primary source of protein. The US study is a follow-on to a previous study comparing a low-glycemic-load Mediterranean diet with added soy protein and phytosterols (plant-based fats) to the American Heart Association's diet plan. In this study, the diet is supplemented with plant-derived substances (phytochemicals) that they believe will improve insulin sensitivity and reduce cardiovascular and metabolic risk factors.

In the Spanish study, 31 obese people (BMI approximately 36) in their mid- to late-thirties were studied. They were not given caloric limits, but their diets included approximately 2 tablespoons of virgin olive oil (2 teaspoons per meal), 1-2 glasses wine daily (half at lunch and half at dinner),
green vegetables and salads to a maximum of 30 g carbohydrate per day, and unlimited protein. Non-nutritive sweeteners were allowed on this diet. Protein was divided into "fish" and "non-fish" (meat, fowl, eggs, shellfish and cheese), with "fish" and "non-fish" being consumed on separate days, and at least four "fish days" per week. In addition, subjects were allowed up to two cups of coffee or tea per day, and required to drink at least three liters of water per day. The subjects were given a standard multivitamin-and-mineral supplement and a calcium supplement; they were also asked to check their urine for ketones using ketostrips.

• Results: After 12 weeks, the subjects lost about 14 kg (30-35 lb), lowered their blood pressure (by about 15 points (millimeters mercury) systolic and 9 points diastolic), lowered their total cholesterol about 10%, significantly dropped their triglyceride levels (from about 218 down to 114 mg/dl), and reduced their fasting blood glucose level about 16 mg/dl. In addition, LDL ("bad") cholesterol levels dropped about 8%, and raised their HDL ("good") cholesterol about 9%. While the subjects were not heavy enough to have moved from "obese" to "overweight" in this time frame, the measured changes moved the patients' statuses from "prehypertension" to "normal blood pressure", from "prediabetic" to "normal", and from "high cholesterol" to "normal cholesterol". Based on the factors used to diagnose it, these subjects would be considered to no longer have metabolic syndrome. The researchers did not measure the beginning and ending percentages of body fat versus muscle mass, but their visual observation suggests that the weight lost was primarily fatty tissue.
• Limitations: The study had a number of limitations, including small size, short duration, highly-selected population, no measurement of total caloric intake, and the possibility that weight loss alone, as well as any of the factors of the program -- either by itself or in combination with others -- may have accounted for these changes. The authors suggest further study with a larger group of people, for a longer period of time, and also comparison with other low-carb diets.

The US researchers' initial viewpoint is that modern diets induce tissue inflammation, resulting in metabolic syndrome. They state that a number of active ingredients in medicinal plants target the pathways of this inflammation, and believe that the addition of these active agents to a low-glycemic-load adaptation of the Mediterranean diet can assist the body in repairing this damage. The US study included 49 patients with metabolic syndrome, average age 53 years, average BMI approximately 34. All subjects had high LDL cholesterol and triglycerides, and had at least two of the other signs used to diagnose metabolic syndrome (low HDL cholesterol, stage I hypertension or drug-treated hypertension, large waist size, and impaired fasting glucose. Half were put on a modified Mediterranean diet alone; the other half were put on the modified diet with the inclusion of phytochemical supplements. The two groups were split out in a way to minimize the initial differences between them.
In this version of the Mediterranean diet, wine was limited to 1 glass per day. Whole grains were allowed, but only one serving per day. Vegetables were mostly limited to very low glycemic load vegetables, with a maximum of one "occasional" serving of a small category of
phytochemical-rich vegetables with a moderate glycemic index (55-70). The only sweeteners allowed were stevia and low-glycemic agave nectar syrup.
The group receiving phytochemical supplementation received a nutritional supplement beverage (powdered) and supplement tablets. All subjects were required to engage in moderate aerobic exercise (at 70-75% target heart rate) for at least 2.5 hours per week. Food cravings, as well as food intake and satiety levels, were monitored (patient-generated logs and surveys). The results were analyzed, accounting for the effects of weight loss, consuming fewer calories, and consuming lower levels of carbohydrate.

• Results: At the end of 12 weeks, the diet-alone subjects lost about 5.7 kg (about 12.5 lb), and the supplemented group about an extra half-pound. While both groups showed lowered total cholesterol, LDL, and triglycerides, the group receiving the supplements saw greater reductions in these readings. Only the group with the supplements had increased HDL cholesterol. The group receiving the supplements were able to lower both systolic and diastolic blood pressure by about 6 points, while those receiving diet alone were only able to lower their systolic blood pressure, by about 4 points. Hemoglobin A1c (HbA1c), a measure of long-term blood glucose levels, went down in both groups, but fasting blood glucose did not drop in the group receiving supplements. Twice the number of subjects in the group receiving supplements were able to move from "having metabolic syndrome" to "normal".

Reliability:
The authors in the Spanish study are associated with the Genetics department of the University of Cordoba and do not report any conflicts of interest. Their bibliographic references are from peer-reviewed journals, mostly in the realm of nutrition.

The authors in the US study all work for the MetaProteomics, a research subsidiary of Metagenics, a company which produces and sells dietary plans, including a number of dietary supplements and meal replacement formulas, which it states will improve the health, weight,
and longevity of people with metabolic syndrome and cardiovascular disease. The MetaProteomics subsidiary is aimed at research into human proteins and how specific chemicals in foods are used by the human body. The bibliographic references are from peer-reviewed journals, and their source research is aimed more at finding the causes of cardiometabolic disease as well as specific chemicals that might lessen the probability of developing these diseases. As employees of a subsidiary of Metagenics, the authors' research is aimed at developing new products (both diets and supplements) for Metagenics to sell.

Both studies are limited in small sample size over short amounts of time; additionally, the Spanish study considers fewer variables.

There are significant differences in the two low-glycemic/low-carb "Mediterranean diets" studied: the Spanish study centers on healthy proteins and fats, while the US study aims more at trying to determine the effect of an anti-inflammatory diet and of the phytochemical
supplements the company sells.

Practical Applications:
Both versions of "Mediterranean diet", unsupplemented, showed favorable changes in cholesterol levels and blood glucose levels. The Spanish study showed greater changes in weight loss, blood pressure, triglycerides, and HDL cholesterol than the US study including supplements; however, the limitations of both studies does not indicate how effective either diet is at maintaining long-term health, or how safe they are over long periods of time.

Any highly-restrictive diet has its limitations, and even some less-restrictive diets may not be suitable for your personal medical conditions. Please consult your doctor and nutritionist before making any large-scale changes to your diet.

This synopsis and comparison was based on the full articles.

Does "dashboard dining" make you fat?

The joint impact on being overweight of self reported behaviours of eating quickly and eating until full : cross sectional survey
Original source: British Medical Journal BMJ 2008;337:a2002
Authors: Koutatsu Maruyama, Shinichi Sato, Tetsuya Ohira, Kenji Maeda, Hiroyuki Noda, Yoshimi Kubota, Setsuko Nishimura, Akihiko Kitamura, Masahiko Kiyama, Takeo Okada, Hironori Imano, Masakazu Nakamura, Yoshinori Ishikawa, Michinori Kurokawa, Satoshi Sasaki, Hiroyasu Iso (corresponding author)
Publication date: 21 October 2008
DOI (digital document ID): 10.1136/bmj.a2002
Requires subscription? No
Publicly-available abstract: Yes

Synopsis:
Researchers in Japan surveyed over 3000 adults for one month, over a period of three years, to see if eating quickly, or eating until one is full, or both, makes people overweight. For the purpose of this research, "overweight" was considered to be having a body mass index (BMI) of greater than 25.
The adults, in one suburban and one rural community in Japan, were asked to rate themselves on how fast or slow they ate and on whether or not they routinely ate until they were full. The self-reporting was confirmed by the subjects' friends.

People with eating disorders such as binge eating disorder, gorging, and anorexia nervosa were excluded from the study, as were people with disordered eating, people with cardiovascular disease, and people who could not tell whether they ate quickly or slowly and/or who could not tell when they'd eaten until full.

The results were adjusted for several variables, including age, caloric intake, physical activity, smoking, and for possible effects of the specific community.
The results were also examined to find out if there was an additive interaction between eating quickly and eating until full (i.e., if one were more likely to be overweight if one both ate quickly and ate until full).

Just over half of the men, and about 58% of the women, said they ate until full. (These people consumed approximately 100 calories more per day, per person than the rest of the population.) Just under half of the men, and over a third of the women, said they ate quickly.

The results suggest that people who eat until full are twice as likely to be overweight as those who walk away from the table slightly hungry; also, that people who eat quickly are twice as likely to be overweight as those who eat slowly. People who eat until full and who eat quickly are over three times as likely to be overweight as those who do not eat quickly, and who leave the table slightly hungry.

The article contains an editorial sidebar that suggests that eating quickly, and/or eating until full, may be contributing factors to overweight and obesity independent of any other eating and exercising behaviors.


Reliability: Despite the large sample size and independent verification, the data were based on self-observation and therefore have the potential of being skewed. On the other hand, many or most of the factors that could give a false reading were accounted for and neutralized. Also, given that people who ate until full consumed 100-150 more calories per day than those who did not, one month may not be sufficient time to draw a theory of causality (that eating rapidly, or eating until full, causes overweight). The article itself does not draw any conclusions as to the reasons for the association between these eating behaviors and overweight, nor does it claim complete independence of factors beyond the ones adjusted for. Given that BMJ appears to posit a direct connection, more stringent research may be needed to test this theory.

Practical Applications: If direct connections can be made between eating quickly, and/or eating until full, and overweight, then it points to the need for education, and possibly abolishing the half-hour-or-shorter meal break, in favor of a longer one.

This synopsis was based on the entire article.