DEAR DR. BLONZ: I have been eating more nuts and seeds, and also adding them to our children's lunches. Walnuts are a favorite. I would like to know their effect on blood lipids and triglycerides. In your reply, I hope you will provide a simple explanation of the difference between blood lipids and triglycerides. -- R.J., Raleigh, North Carolina

DEAR R.J.: "Lipids" is an umbrella term for a group of chemicals that includes fats (solid at room temperature), oils (liquid at room temperature), fatty acids, phospholipids, waxes and steroids. They are all composed primarily of carbon atoms in the form of chains or ring structures. Each type of lipid has a structure that sets it apart from the others. All lipids share one characteristic: They cannot dissolve in water, but instead dissolve in organic solvents such as mineral spirits or cleaning fluids. Some lipids can have water-soluble elements attached. Triglycerides also belong to the lipid family, but they're the form in which fats and oils are packaged in the body. And to complete the picture, cholesterol, a type of steroid, is another member of the lipid family.

About 80% of the calories in walnuts come from fat. Eating walnuts could have a variable effect on one's blood triglyceride level, depending on the amount eaten, other items in the meal and any predisposition one might have toward elevated blood lipid levels.

An interesting side note is that nuts, when eaten as a pre-meal snack, can contribute to satiety and decrease caloric intake. A classic study involving university students found that consuming one ounce of walnuts as a pre-meal snack was associated with a reduction in total calories consumed (nuts plus the meal). One ounce of walnuts (14 halves) provides 185 calories, 18 grams of fat and 2 grams of dietary fiber.

There can be differences in health effects between the various types of nuts and seeds, but the general impacts are comparable. There are similar results with peanuts, often regarded as nuts but actually classified as legumes. On a personal note, I rotate between individual nuts and blends of almonds, cashews, pistachios, walnuts, peanuts and pecans, often making a trail mix with added dried fruit and a few dark chocolate chips.

DEAR DR. BLONZ: What is vitamin A palmitate? I know palmitic acid is one of the saturated fats. Is it harmful in diets for those of us who have a cholesterol problem? Why is this form of vitamin A in so many foods? -- V.H., San Diego, California

DEAR V.H.: Vitamin A can exist in several related chemical forms. One of these compounds is made from vitamin A and palmitic acid, a saturated fatty acid. This form of vitamin A is stable and relatively inexpensive, making it the compound of choice for fortifying foods. The small amount of palmitic acid you would receive from vitamin A palmitate (also called retinyl palmitate) would be of little consequence to your cholesterol problem.

To put some numbers here, the daily value of vitamin A is 900 μg RAE (micrograms of retinol activity equivalents), also referred to as 3,000 IU. This level will be in 1.65 mg of vitamin A palmitate, which contains a paltry 0.8 mg of palmitic acid.

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: I have a question concerning recommended servings of foods, how they have been determined over the years and the confusion with food labels. It can be unclear when checking serving sizes on labels and those used to make recommendations, such as the USDA food pyramid. Why can't these use the same standards? -- J.L., San Francisco, California

DEAR J.L.: Food serving sizes on the food pyramid and Nutrition Facts labels have evolved over the years, always attempting, at least in theory, to be consistent with those used in USDA dietary recommendations (see myplate.gov).

In recent years, products have had their individual container size reduced. Many in the food and beverage industry have opted for unannounced downsizing, allowing, at least in theory, for price maintenance. (If one company does it, others tend to follow, so their products are not priced above their competition.) However, the influences of the pandemic, inflation and tariffs have overwhelmed any ability of minor volume reductions to stabilize food prices.

Nutrition Facts should align with the USDA serving sizes whenever possible; this typically occurs when a container contains multiple servings. But be aware that products often focus on the container size. For example, checking the Nutrition Facts label of a 64-ounce container of vegetable juice, such as V8, would display nutrients in one serving (as per the USDA) along with the number of servings per container. However, if you were to check smaller containers of the same juice, such as their 5.5-ounce and 11.5-ounce cans, you would find that both their Nutrition Facts labels reflect the nutrients in a single-can serving.

Best to use Nutrition Facts to help compare brands and options. The amount of "added sugars" should always be on your radar for healthy eating.

DEAR DR. BLONZ: I am seeking your advice on a comparison between psyllium husk (I take 4 teaspoons daily) and a new product made from guar gum. This new option is pleasant to take, non-thickening and grit-free, with a flavor-free option. But is it equally effective? Please reply and let me know which one to choose. Thank you so very much. -- J.S., Raleigh, North Carolina

DEAR J.S.: Many whole-grain foods, fruits and vegetables are rich in nutrients and can provide the body with the dietary fiber it needs. If you have been instructed by your health professional to take a fiber supplement, either of these products will accomplish that goal. Pick whichever one you feel most comfortable with, and be sure to follow the label directions. For a good discussion of dietary fiber, check the MedlinePlus article at b.link/j43qu.

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: Our son, now 13, has grown about four inches in the past year. Lately, he has mentioned experiencing some muscular pains when playing soccer, often stating that the soles of his feet hurt. He describes the pain as more annoying than severe. The coach and I have instructed him to stretch and warm up prior to any intense efforts. I feel that he also needs to address other areas, such as nutrition and vitamin and mineral supplementation, especially since he does not eat well. What might you suggest for a child regarding vitamin and mineral supplementation? -- D.J., Walnut Creek, California

DEAR D.J.: Generally speaking, it is not unusual for rapidly growing children to experience minor aches and pains as they mature into their adult body. Discomfort may be caused by muscles and tendons that become too tight for their rapidly growing long bones. These types of "growing pains" are often experienced at night, when most growth occurs, but they can also be felt during the day. (For more on growing pains, see b.link/6tpy7hg.)

You mention pains in your son's foot. Each foot contains 26 separate bones (1/8 the total number in our entire skeleton), and some tendons pass around the ankle to control the movements of the foot. Discuss with the health professional who, ideally, has been tracking his growth over the years, whether his discomfort could be a side effect of his rapid growth. You may learn that stretching before the workout, along with periods of rest during the game, can be beneficial.

And please don't ignore the obvious. I realize that a child's rapidly growing body can run through clothing sizes in a way that sends shivers through one's bank balance, but if not already done, make sure that your son's shoes -- especially his soccer cleats -- fit correctly.

As for your nutrition concerns, any period of rapid growth relies on the creation of new body tissue, and that means an ample supply of raw materials, such as protein and minerals, plus the vitamins and dietary energy (fat and carbohydrate) to keep the process fueled and on an even keel.

Good eating habits are often overlooked during the teenage years. At times, we, as parents, might wonder how our children are able to grow and remain in good health, given what they eat.

There are limits to what a parent can accomplish during their child's adolescence. Playing a parental power card may backfire, as these are the very years when a child feels the drive to establish their independence. One key is to set a good example by what you eat and to keep him involved as much as possible in decisions that relate to food choices and food preparation.

You ask about vitamin and mineral supplements. I believe that food must always be the focus. If you want a supplement, opt for a general, all-purpose multi-vitamin/mineral tablet or powder, with an eye on providing those nutrients that are missing from his daily diet.

Finally, many adolescents take pride in seeing their bodies change and mature. If they can be made to understand the benefits of using healthful, whole foods to provide the raw materials and nutrients the body relies on to build its muscles, bones and skin -- and that this is something over which they have control -- they may be more willing to make improvements.

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.