DEAR DR. BLONZ: I am aware of the dangers of trans fats, but I am also concerned that some foods, like shortening, still use hydrogenated fats. Are these any better than the trans fats in partially hydrogenated shortening? One brand now uses “fully hydrogenated,” rather than partially. Is that better or worse for cooking? -- F.C., San Jose, California

DEAR F.C.: The quick explanation is that a fully hydrogenated shortening does not have any trans fats. Imagine a road stretching between an unprocessed, unsaturated liquid vegetable oil and a solid block of fully hydrogenated fat. On this road, partially hydrogenated fats are somewhere in the middle. The important issue here is that the process of partial hydrogenation is what creates trans fatty acids, or TFAs, which are unsaturated fatty acids that have an unusual structure causing a range of health problems in the body.

Partially hydrogenated oils used for deep-frying are different from those used in baking, breading or candy coatings. Blends with different proportions of TFAs might be more spreadable, have an increased shelf life or have some other desired feature, but the advantages of these artificial fats are all on the manufacturer’s side of the equation. They provide no health benefits for the human body.

Due to their negative health effects, and the lack of any upside, the Food and Drug Administration began requiring trans fats to be declared on food labels. With the advent of having to reveal the number of grams per serving, food processors sought other methods to make their fats spreadable.

In one method, known as interesterification (IE), food processors use oils together with fully hydrogenated fats and create a mixture with the desired characteristics. It’s not something you can do at home with a measuring cup. This type of reconfiguration involves shuffling fatty acids around on triglycerides using enzymes or chemical catalysts. Many hydrogenated -- but trans fat-free -- shortenings on the market are made this way.

IE has been available to food processors for a while, but since it was less costly to keep using partial hydrogenation, and there was no public outcry for alternatives, it was not widely used until recently. Fully hydrogenated products made using IE can have zero trans fats -- or, from a regulatory standpoint, less than 0.5 grams of trans fats per serving, meaning “no trans fats” can be declared on the Nutrition Facts label.

While this new family of shortenings with no trans fats is a positive development, the jury is still out as to whether the use of IE fats might also give rise to health issues. There’s also the possibility that fats naturally high in saturates, such as palm oil and coconut oil -- or even fully hydrogenated oils -- used in blends might be the way to go. Tropical oils, long suffering from a public-relations black eye, have now gotten their green card.

As for whether they’re any better or worse in the kitchen, IE shortening products have undergone performance testing, so you can expect them to be functionally comparable to the older versions. Just as there are brand-to-brand variances with other ingredients, you may need to do some testing to find the shortening that works best with your recipes. But it would be prudent to keep IE fats to a minimum, given that we don’t have a complete picture on their impact on health.

Send questions to: “On Nutrition,” Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.

DEAR DR. BLONZ: In doing a research paper on health issues faced by indigenous peoples, I came across the issue of the Pima American Indians in Arizona, who have a very high incidence of Type 2 diabetes. Is this a genetic issue, or a dietary and lifestyle issue? -- J.D., Casa Grande, Arizona

DEAR J.D.: It’s both. The Pima appear to have a genetic component that is not serving them well under the current style of eating in the United States. It is called a thrifty genotype, and it provides survival advantages when there is an irregular food supply by conferring maximum efficiency in the processing and utilization of dietary energy (calories).

Pima Indians live in northwest Mexico and the southwestern U.S., having migrated there from remote mountainous regions in Peru, where a good number remain. In these areas, there is an inconsistent food supply throughout the year. Over the millennia, the Pima in Peru and Mexico adapted to the sparse availability of food in these regions, and as a group, they tend to be slim and do not suffer from Type 2 diabetes.

The Pima who migrated to what is now the United States, however, no longer have to cope with an irregular food supply, and are now experiencing an epidemic of obesity and Type 2 diabetes attributable to this environmental change in their diet.

Insulin resistance and hyperinsulinemia have been identified in the Americanized Pima Indian population. Scientists from around the world continue to study this population because it offers a rare insight into the independent roles of genes and environment on the risk of disease. Studies continue to report on the critical roles of food selection and increased physical activity in helping reduce the risk of Type 2 diabetes in this population. There is an interesting discussion on this topic at b.link/pima85.

DEAR DR. BLONZ: I need to up my level of dietary fiber. I want something convenient, but I am seeking taste, not cardboard. What do you consider to be the best foods that are rich in fiber? -- N.F., San Jose, California

DEAR N.F.: Americans tend to eat rather low on the fiber scale, and population studies continually find that increased consumption of dietary fiber is associated with a range of health benefits.

In terms of convenience, there’s no better way to start the day than with a bowl of fiber-rich whole-grain cereal topped by some fresh or dried fruit. Setting the requisite time aside in the morning to have a healthful breakfast can be an important adjunct to your health.

With or without the cereal, dried fruits are on my list of excellent fiber-filled foods. They are an often-overlooked fiber source with a great variety of rich fruit flavors, and the fact that they are dried gives them an extended shelf life. Combining them with various nuts and seeds, even tossing in a few dark chocolate chips and coconut flakes, makes a healthful, fiber-rich snack or mini-meal that can be available throughout the day. This mix is also a great real-food option for your child’s lunchbox.

Next, we have vegetables, whole grains and legumes (beans), all of which have a high fiber content. No cardboard on that list. Fiber supplements can have a role, but first, focus on foods naturally high in fiber. They come with an assortment of other important nutrients and phytochemicals. For more, check the FDA’s fact sheet on dietary fiber at b.link/pdf34.

Send questions to: “On Nutrition,” Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.

DEAR DR. BLONZ: On a TV show, I watched a hospital nutritionist cook a chicken breast by putting it in a resealable plastic bag, submerging it in a pan of water, bringing the water to a boil, turning off the heat and letting the pot rest for two hours. I am skeptical of this method, because it doesn’t seem that the meat stays hot enough for long enough to be safe. In fact, it sounds like a recipe for promoting bacterial growth, not to mention the dubious wisdom of boiling a plastic bag. What do you think of this cooking method? -- A.M., Castro Valley, California

DEAR A.M.: First, it should be noted that, while it may sound similar, the method you describe is different from “sous vide” -- an established cooking method gaining popularity in recent years. (More on sous vide below.)

The main concern with any poultry, no matter how it’s cooked, is salmonella bacteria. In the process you describe, a chicken breast is put in a plastic bag, which is then put into a pan of water that’s brought to a boil (212 degrees F). That’s well over the temperature needed to kill those bugs. However, meats are only as safe as the least-cooked portion, and chicken breasts come in a range of sizes and thicknesses.

Our question, then, becomes: Once the heat is turned off, is the thermal mass of the pan and the boiled water sufficient to raise the internal temperature throughout the entire piece of chicken to a level sufficient to zap the bacteria?

According to the FDA, the safe minimum temperature for poultry is 165 degrees F (see b.link/food51). But it should be understood that time is a factor, as well as temperature. For example: Most recommendations say to cook poultry until a thermometer reaches at least 165 degrees F in the thickest part of the meat. It will then be safe to eat. But if the poultry is cooked to 145 degrees F and kept at that temperature for at least nine minutes, you could accomplish the same elimination of bacteria. That, however, requires closer attention to the cooking process, not a one-time temperature read. (Check out the interesting discussion of time and temperature poultry cooking at b.link/chicken97.)

So, how can we be assured that the technique you saw will produce chicken that is safe to eat? That TV technique presents risk variables, with no real way of assuring the safety of the results. The bag must be a material suitable for boiling, and since air is not a great conductor of heat, there must be a step to draw all air out of the bag, such as with a vacuum-sealing device. Handling must eliminate risks of cross-contamination from surfaces that touched the uncooked poultry. Another variable is how rapidly the water temperature drops after boiling. It will cool at one speed if using a metal pan in a cool room, and another if resting post-boil on a conductive surface that drains the heat.

These factors -- the bag material, the presence or absence of air, the chance of cross-contamination, and the water-cooling speed -- are all potential risks. So without testing, this is not a method I could recommend.

You might instead consider the sous vide method. Here, the food is put into a bag, the air is removed, and the bag gets submerged in water that is then heated to around 145 degrees F and kept there for one to four hours. The advantage here is that the sous vide device heats the water to a specific temperature, then circulates and maintains it for a set period. (For more on sous vide, see b.link/vide10.)

Send questions to: “On Nutrition,” Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.