New York/PRNewswire -- Most Americans (87%) say they are making an effort to eat healthy -- and with good reason, as a majority say they or someone in their household monitor or restrict their intake of a nutritional component like gluten or sugar, according to a new Harris Poll. Six in 10 American adults (60%, a slight uptick from 57% in 2011) say they restrict at least one nutritional component from their diet.

These are some of the results of The Harris Poll of 2,234 adults surveyed online between March 12 and 17, 2014. Sugar (36%, up from 32% in 2011) and sodium/salt (36%) top the list of ingredients American households have at least one person restricting or monitoring, followed by carbohydrates (22%). Over one in 10 say they or a member of their household monitors/restricts intake of dairy (13%, up from 10% in 2011), meat or meat products (also 13%, up from 10%) and lactose (11%). The percentage saying they or someone in their household monitors or restricts gluten intake has nearly doubled over the past three years, to 10% today from 6% in 2011.

"With six in 10 American households having at least one member restricting certain foods from their diet, this raises important implications for the food industry as a whole," says Todd Hale, senior vice president Consumer Insights, Nielsen. "We've seen that a restriction for one, especially in the case of allergens and other health risks, can turn into a household ban. This can present both a challenge and an opportunity for retailers and food manufacturers."

Perhaps not surprisingly, Matures (73%) are more likely than any other generation (54% Millennials, 62% Gen Xers, 60% Baby Boomers) to say they or someone in their household restrict or monitor intake of at least one of the tested nutritional factors.

"As Americans age, they develop stronger opinions and restrictions around nutritional choices. Those 68 and older are the most likely of all generations to pay close attention to nutritional labels and restrict corresponding dietary choices such as sodium or sugar," said Hale. "Given the number of people, young and old, describing themselves as knowledgeable about food labels and making an effort to eat healthy, these generational divides suggest that actual implementation of change may stem more from necessity than knowledge."

When consumers consider making a food and beverage purchase, freshness is the most important factor, with nine in ten U.S. adults (89%) considering it important.

Eight in 10 say fiber is important (80%), while roughly three-fourths say the same for whole grain (77%), calories (75%), portion size (73%) and fat content (73%).

Roughly seven in 10 place importance on sodium or salt (71%), saturated fat (71%) and dairy (69%), while roughly two-thirds indicate the same for sugar (68%), natural (68%) and carbohydrates (67%).

Looking at more specialized nutritional factors, 49% place importance on whether food and beverage products are genetically modified, while 45% say the same for organic. Nearly four in 10 place importance on glycemic index (38%), roughly three in 10 say the same for lactose (31%) and gluten (28%), and knowing whether items are vegan is important to just under two in 10 (18%)

Most of these factors' perceived importance increases among older Americans, though with some exceptions. The percentage placing importance on knowing whether food or beverages are genetically modified hovers at roughly the halfway mark across generations (48% Millennials, 51% Gen Xers, 49% Baby Boomers, 48% Matures), while younger Americans are more likely to place importance on whether items are organic (55%, 50%, 38% and 35%, respectively), contain lactose (37%, 28%, 28% and 27%, respectively) and are vegan (27%, 19%, 13% and 12%, respectively).

Looking to diet and/or weight management, roughly eight in ten Americans consider protein (82%) and calories (78%) to be important considerations, while roughly three-fourths indicate the same for fat (77%), whole grain (76%), saturated fat (75%) and sugar (74%). Roughly seven in 10 believe carbohydrates (72%), cholesterol (70%) and sodium (68%) are important in this regard, while just over six in 10 say the same for hydrogenated oil (62%).