Nutritional Science & Dietetics Flashcards

During prolonged fasting, which metabolic state predominates to spare muscle protein?

Answer: Ketosis

Ketosis allows the brain and other tissues to use ketone bodies as an alternative fuel, reducing the need to catabolize muscle protein for gluconeogenesis.

Which vitamin functions as a coenzyme in transamination reactions involving amino acid metabolism?

Answer: Pyridoxine (B6)

Pyridoxal phosphate (PLP), the active form of vitamin B6, is the coenzyme required by aminotransferases (transaminases) that transfer amino groups between molecules.

A Registered Dietitian Nutritionist calculates a patient's protein needs at 1.5 g/kg/day. The patient weighs 176 lbs. How many grams of protein are required daily?

Answer: 120 g

176 lbs ÷ 2.2 = 80 kg; 80 kg × 1.5 g/kg = 120 g of protein per day.

Which mineral is a structural component of thyroid hormones T3 and T4?

Answer: Iodine

Iodine is directly incorporated into the thyroid hormones triiodothyronine (T3) and thyroxine (T4), which regulate metabolic rate.

The glycemic index (GI) of a food is most directly affected by which factor?

Answer: Starch structure and fiber content

The ratio of amylose to amylopectin and the amount and type of dietary fiber primarily determine how rapidly a food raises blood glucose, thus affecting GI.

Which assessment method most accurately measures total body fat percentage in a clinical setting?

Answer: Dual-energy X-ray absorptiometry (DXA)

DXA is considered the gold standard for body composition assessment in clinical settings because it directly measures fat mass, lean mass, and bone mineral density.

A food label lists 0 g trans fat per serving, but the ingredients include 'partially hydrogenated oil.' What does this indicate?

Answer: The product may contain up to 0.5 g trans fat per serving due to FDA rounding rules

FDA labeling rules allow rounding to 0 g if trans fat content is less than 0.5 g per serving, so foods containing partially hydrogenated oils may still have small amounts.