DEAR DR. BLONZ: As part of my plan to drop weight, I gave up sweetened sodas and began drinking a costly weight-loss drink. I dropped almost 10 pounds in a couple of weeks. I went off that drink, and even though I never went back to soda, the weight came back. I’m trying to figure this out, including whether I was doing anything dangerous to my body. The product said it contained no stimulants, which I should avoid. How could I have handled it so that the weight stayed off? -- M.G., Tulsa, Oklahoma

DEAR M.G.: You would think that the purpose of a weight-reduction diet was simply to drop weight, but this is not entirely accurate. More specifically, the goal is to reduce excess body fat. Diet products might help you reduce weight while failing to make a significant dent in your stores of surplus fat. How can that be?

Fat is the most calorie-dense material we consume; it has 9 calories per gram, compared to 4 per gram for protein and carbohydrates. (Also be aware that there are 7 calories per gram of alcohol.) Our energy storage tissue, or adipose, is made up almost entirely of fat. While estimates vary, the standard is that the body needs to spend about 3,500 more calories than it takes in to lose a pound of body fat. If you were to cut your food intake by 500 calories per day, you would lose about a pound of body fat in a week.

Interestingly, less of a calorie deficit is needed to lose a pound of body protein. This is because the protein tissue in our muscles and organs is about 80% water by weight. If a diet causes the breakdown of body protein, the numbers on the scale can drop rapidly, but the major component will be the loss of water, not fat.

Some weight-loss products are diuretics, which cause the body to lose water, not fat. Others contain laxatives, which can also make the numbers on the scale go down, but in that case, it is a decrease in the amount of waste in queue for elimination, not a drop of excess body fat.

Your experience suggests that your product contained diuretics, laxatives or both; that would explain why so much weight was lost, only to return so quickly.

Stimulants, which rev up your metabolism, are another way to lose weight, but they are risky business. Stimulants can be dangerous for anyone with existing health conditions, including cardiovascular disease, hypertension or anxiety disorders. I am hoping your product’s label is accurate in its claim that it is free of such substances.

Weight-loss success takes time, determination and a good plan. Quick fixes tend to fail the test of time. I commend you for stopping your intake of excess caloric soda, but relying solely on a weight-loss drink (or diet pills) does not bode well for long-term chances. Better to find a plan that includes a healthful, balanced diet, a good selection from all the food groups and a solid activity component. By shifting to more healthful foods and increasing activity, you make gradual adjustments. The results may be less dramatic, but there is a greater chance for long-term success. Another benefit: No more costly products to buy.

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: What is the latest thinking about the maxim that we should not eat fruits and vegetables at the same meal? For a longstanding myth, it certainly has taken its time to be soundly debunked. -- B.T., Tulsa, Oklahoma

DEAR B.T.: There is no one way of eating that works for everyone. We all have our quirks and twists on the physiological “rules” of the day, so what works for one might upset another. If there were to be a generalization in this matter, though, it would be that there is no evidence that fruits and vegetables need to be consumed separately.

The human digestive system is well-designed for mixed meals. Our body, however, does adjust to our eating habits, and radical shifts can lead to upset. This does not necessarily mean such a shift is a bad thing -- as long as it’s a change in a healthful direction -- but the issue may be the speed at which it’s instituted. If you are going to make changes, do so gradually.

DEAR DR. BLONZ: I understand there are beneficial ingredients in chocolate, including antioxidants. Are these substances found in the cocoa powder or in the cocoa fat? If it is in the fat, would that mean that the only way to get the benefits is to eat the full-fat kind of chocolate? -- C.H., Los Angeles

DEAR C.H.: Research on chocolate has indeed identified the presence of beneficial compounds. These compounds, known as flavonoids, have been found in the cocoa powder as well as the whole chocolate confection. Dark chocolate tends to contain more than milk chocolate; white chocolate, which contains cocoa butter (fat), contains little, if any, of the flavonoids. As for whether having cocoa powder is a “better” way of getting the benefits of the chocolate, that is a matter of personal preference. There are plenty of foods with wonderful attributes. Eat chocolate not because it is prescriptive, but because you enjoy it.

DEAR DR. BLONZ: I need your advice concerning a choice between psyllium husk (I take 4 teaspoons daily) and a new fiber supplement made from partially hydrolyzed guar gum. This new product is pleasant to take, nonthickening, has no grit and is flavor-free. But is it equally effective? -- I.K., Anderson, South Carolina

DEAR I.K.: There are many excellent whole-grain foods, fruits, and vegetables that are rich in nutrients and can provide the dietary fiber the body 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. And be sure to take it slow (see the first question, above), if this is a new component to your diet.

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 am shifting to tofu instead of meat, but I want some guidance as to how much it will take to meet my protein requirements. I weigh 105 pounds and am 5 feet tall, and 1,000 calories is about as much as I can consume in a day without gaining weight. I want to have some idea of how much tofu I should have daily. -- R.V., via email

DEAR R.V.: As a general baseline, protein requirements for adults are about 3.6 grams of protein per 10 pounds of body weight -- so, multiply your weight in pounds times 0.36. Those routinely involved with intense physical activity may need twice that amount. The typical American, even if sedentary, tends to consume more than enough protein -- even above the level recommended for active adults.

One serving of meat is approximately 3 ounces, equivalent in size to a pack of playing cards. If trimmed of visible fat, this serving would contain around 25 grams of protein. One cup of extra-firm tofu contains an equivalent amount of protein.

I don’t think it wise for a single food to become the focus of any diet. Consider including vegetarian sources of protein such as nuts, seeds, grains and legumes -- or fish, poultry and dairy, if you are an omnivore. Red meat does not represent a health problem when part of a plant-based, whole-food diet. The issue is not so much its source as its place among the other foods you eat.

Concerning tofu, it is made from soybeans that are soaked, crushed, cooked and filtered. Calcium sulfate is typically added, causing the soy pulp to form a gel. The water is then removed as the soy is pressed into cakes. Tofu has a relatively high content of polyunsaturated fats, a type that can turn rancid when exposed to air -- especially warm air. If fresh, tofu should be kept refrigerated and in water. When you purchase fresh tofu, make sure it has been properly stored. You should take it home in a well-sealed plastic bag that contains water. There are other options, one of which is to buy cakes of tofu in refrigerated, commercially sealed, water-filled packages; another is to buy tofu that is vacuum-sealed in an aseptic carton.

Discard tofu if the storage water becomes cloudy, if a slippery film develops on the surface or if you notice any unusual smells. Also, the tofu should be discarded if it takes on a pinkish tinge -- usually the effect of exposure to air. If the water is changed daily, fresh tofu can last up to two weeks in the refrigerator.

Finally, a bit about your daily calorie comment. Checking the counter at b.link/calcounter reveals that your intake is on the light side for someone of your height and weight. A moderately active adult requires about 15 calories per pound of body weight; if that’s you, it translates to a daily caloric requirement of 1,575 calories. This suggests there might be room on your plate for more food. All these data come from population averages, so keep in mind that the greater your lean body (muscle) mass, the more energy it takes -- even if you are sitting around doing nothing.

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.