Final answer:
Individuals with a balanced diet are not at risk for developing a thiamin deficiency because a variety of thiamin-rich foods in their diet meets the daily requirement. Thiamin deficiencies can cause serious health issues, but a well-rounded diet prevents this.
Step-by-step explanation:
Out of the groups listed, individuals with a balanced diet would not be at risk for developing a thiamin deficiency. Thiamin, also known as vitamin B₁, is a nutrient that should be provided daily in the diet, as the body cannot store it for long periods; skeletal muscle can only retain it for a short duration, and the brain cannot retain it at all. A balanced diet that includes a variety of thiamin-rich foods, such as rice bran, wheat bran, whole grains, nuts, germinating seeds, pulses, beans, lentils, yeast, liver, eggs, fish, meat, and milk, should provide the daily requirement of thiamin, which ranges from 1.0 to 2.0 mg/day depending on the individual's energy needs.
Thiamin deficiencies can result in serious health issues, including loss of appetite, Beri-Beri, Wernicke's encephalopathy, and others. It is particularly important for children, pregnant women, and elderly individuals to maintain adequate thiamin intake due to their higher relative needs or absorption challenges. But for someone consuming a well-balanced diet that meets all their nutritional requirements, thiamin deficiency is highly unlikely.