Brown R, Gray AR, Chua MG, Ware L, Chisholm A, Tey SL. Is a handful an effective way to guide nut recommendations? Int J Environ Res Public Health. 2021;18(15):7812.
The objective of this study was to quantify the actual grams of nuts people choose when using various descriptive terms (handful, large/small, usual, or 30 g).
Recommending a “handful” of nuts translates to more than 30 g of nuts in the perception of roughly 8 out of 10 people.
A descriptive study designed to determine the weight of presumed portions of nuts when participants were instructed to take various types of “handfuls.”
Investigators recruited 124 adults from Dunedin, New Zealand, with 120 subjects included in the final analysis (75 women and 45 men). The average age was 34 years (24–51). There were approximately equal numbers of subjects who were normal weight, overweight, and obese.
The ethnicities of all subjects included NZ European (58, 48.3%), Māori (7, 5.8%), Pacific Island (2, 1.7%), Asian (50, 41.7%), and Other (3, 2.5%).
Exclusion: Anyone allergic or intolerant to nuts. The final number of subjects included in the study was 120.
After subjects completed a questionnaire about their usual nut consumption and rated their overall hunger, they were then randomized to receive 3 of 6 nut types and instructed to take the nuts from a bowl based on what they perceived as:
- a “usual serving” of nuts,
- a “handful” of nuts
- a “small handful” of nuts
- a “large handful” of nuts, and
- equal to a “30 g serving” of nuts.
Study Parameters Assessed
The parameters assessed included subjects’ baseline nut consumption, overall rated hunger (from “not at all” to “extremely” hungry), and perception of the above 5 nut portions.
After subjects completed the experiment, investigators weighed each of the 5 perceived portions and recorded the height of each participant (as a surrogate for hand size).
The primary outcome was to determine if the term “handful” is a useful and accurate way to guide consumers to eat about 30 g of nuts per day to reduce incidence of chronic disease.
The key findings in this study were that the subjects’ estimates of the 5 different portions showed wide variability, and these varied between nut types as well.
The variability between subjects was considerable: Across all nut types, a “handful” ranged from 9.1 g to 106.3 g. For a 30 g serving the range was from 6.0 g to 148.5 g.
The median weights of nuts for all participants and all nut types combined were as follow:
- a “usual serving” = 24.8 g
- a “handful” = 36.3 g
- a “small handful” = 16.7 g
- a “large handful” = 61.3 g
- “30 g serving” = 28.7 g
Nut Portions: Overall 83.0% of subjects chose at least 80% of the recommended 30 gportion when they were told to take a “handful” of nuts as compared to 62.7% when they were told a “30 g serving” and 52% when instructed to take a “usual serving.” This suggests that the term “handful” may be a more useful general term to use when making recommendations for nut intake compared to saying “30 grams.”
Nut Type: Overall, more subjects (90%) chose an amount equal to at least 80% of the recommendation for almonds and macadamias, whereas only 78.3% did so for hazelnuts, 72.9% for walnuts, and 71.7% for cashews.
This research received no external funding.
Practice Implications & Limitations
Current nut consumption guidelines in many countries recommend consuming 28 to 30 g of nuts, which is equal to about 1 ounce.1 But many people may not be familiar with what 1 ounce of nuts looks like. In an attempt to determine useful, practical, and accurate language to guide recommendations, this study weighed the nut portions that result from several of the common terms used for recommending nut consumption. The results of this study suggest that of the 5 terms, using the term “handful” was the most reliable and useful way to get the majority of subjects to consume at least 80% of the 30 g/day recommendation.
The study noted some other findings as they related to gender differences and nut type as well. For example, when nut types were combined, for “large handful,” “handful,” and “usual serving,” those meeting at least 80% of the recommendation were 3, 9, and 15 percentage points higher in males compared to females. Investigators also noted numerical differences by nut type. When asked to take a “handful,” 90% of participants chose an amount equal to at least 80% of the recommendation for almonds and macadamias, whereas only 78.3% and 72.9% did so for hazelnuts and walnuts respectively. For the estimated “30 g serving,” 53.3% chose amounts equal to at least 80% of the recommendation for almonds, compared to 71.7% of participants for cashews.
But many people may not be familiar with what 1 ounce of nuts looks like."
The authors identified a number of limitations to be considered when interpreting the findings. First, they did not measure the hand size of individuals and so cannot draw any conclusions about the relationship between portion size and hand size. Also, they indicate that “sample was not representative of the New Zealand population, with a higher percentage of females, and predominantly Caucasian and Asian.” They did not measure the physical activity level for each individual and, instead, used the value for light activity as a conservative estimate of energy requirements.
Ultimately, a “handful” resulted in a high proportion of individuals taking at least 80% of the 30 g/day of nuts for good health. This study showed that “a handful” is indeed a useful and practical means of recommending the correct portion size for daily nut consumption.