**3. Results**

#### *3.1. Demographic Data*

There were significant di fferences among countries for all demographic data. Mexico showed the highest women proportion while Germany the lowest (25% di fference, small e ffect). Age, body mass, and height comparisons showed a large e ffect. The oldest participants came from Mexico, Germany, and U.K. in contrast to those in U.S.A. (8-year di fference). The heaviest participants belonged to U.S.A. (20 kg di fference vs. Mexico), and U.S.A. and Germany showed the tallest participants (13 cm di fference vs. Mexico). The B.M.I. comparison showed a medium e ffect with U.S.A. having the heaviest participants (3.3 units di fference vs. Germany) (Table 2). A similar pattern was observed in women (Table S1) and men (Table S2).

#### *3.2. Protein Intake*

For absolute protein intake (g), U.K., U.S.A., and Germany showed the highest protein consumption per day (19 g di fference vs. Mexico, medium e ffect). Mexico, U.S.A., and Germany showed the highest intake at breakfast (3 g di fference vs. U.K., trivial e ffect). In comparison, U.K. and U.S.A. showed the highest intake at dinner (20 g di fference vs. Mexico, large e ffect). There were no significant di fferences among countries for protein intake at lunch (Table 2).

For relative protein intake (g/kg), U.K. showed the highest intake per day (0.22 g/kg di fference vs. U.S.A., small e ffect). Mexico showed the highest intake at breakfast (0.09 g/kg di fference vs. U.S.A., medium e ffect). U.K. and Mexico showed the highest intake at lunch (0.15 g/kg di fference vs. U.S.A., medium e ffect). U.K. showed the highest intake at dinner (0.29 g/kg di fference vs. Mexico, large e ffect) (Table 2).

Analyzing the percentage of meal contribution to total protein intake, Germany, and Mexico ate most of their daily protein at lunch, whereas U.S.A. and U.K. did it at dinner. Mexico showed the highest breakfast (13% di fference vs. U.K., medium e ffect) and lunch contribution (12% di fference vs. U.S.A., medium e ffect), whereas U.S.A. and U.K. showed the highest dinner contribution (19% di fference vs. Mexico, large e ffect). In terms of the PDCV, Germany showed the evenest protein distribution (−0.17 units di fference vs. U.K., small e ffect) (Table 2). The comparisons divided by sex showed a very similar pattern to that observed of the whole sample, with slight di fferences in which countries di ffer from one another (Tables S1 and S2). However, it is remarkable that there were no significant di fferences among countries at breakfast and lunch (g) nor per day and breakfast (g/kg) in men (Table S2).



*Nutrients* **2020**, *12*, 3156

(*p* ≤ 0.05) within each variable.

#### *3.3. Inadequate Protein Intake per Day*

There were significant differences among countries for IPID-0.8, IPID-1.0, but not IPID-1.2. For IPID-0.8, the highest percentage was observed in U.S.A. (43.0%) and Mexico (42.2%) (35% difference vs. U.K., small effect). For IPID-1.0, U.S.A. (61.5%), Mexico (61.5%), and Germany (60.8%) showed the highest percentages (35% difference vs. U.K., small effect). For IPID-1.2, percentages ranged from 65.8% in U.K. to 83.5% in Germany (Figure 1). A similar pattern was observed in women. However, in men, there were no significant differences among countries for any cut point (Figure S1).

**Figure 1.** Comparison of inadequate protein intake per day with different cut points among four countries. Bars represent the percentage of inadequate protein intake per day; whiskers represent 95% confidence intervals. *p*-values and ϕ statistic are for comparisons among countries within cut points (χ<sup>2</sup> test of independence). Bars not sharing a similar letter (a, b, c) denote significant differences (*p* ≤ 0.05) among countries within cut points (*t*-test for proportions with Bonferroni correction). g/kg/day: grams of protein per kilogram of body mass per day; U.K.: United Kingdom; U.S.A.: United States of America. Detailed data can be found in Table S3.

#### *3.4. Inadequate Protein Intake per Meal*

For IPIM-30, there were no significant differences among countries at breakfast (range 91.5% in U.S.A. to 97.4% in U.K.) and lunch (range 63.2% in U.K. to 77.0% in U.S.A.). However, there were significant differences at dinner, where Mexico (96.8%) showed the highest percentage (60% difference vs. U.K., medium effect) (Figure 2a). The pattern was very similar when comparisons were separated by sex (Figure S2a,b).

For IPIM-0.4, there were significant differences among countries for the three meals. At breakfast, U.K. (97.4%), U.S.A. (94.0%), and Germany (90.7%) showed the highest percentages (20% difference vs. Mexico, small effect). At lunch, U.S.A. (80.5%) and Germany (72.2%) showed the highest percentages (31% difference vs. Mexico, small effect). At dinner, Mexico (92.0%) showed the highest percentage (61% difference vs. U.K., medium effect) (Figure 2b). The pattern was very similar when comparisons were separated by sex (Figure S2c,d).

**Figure 2.** Comparison of inadequate protein intake per meal (breakfast, lunch, and dinner) among four countries depending on the protein content at each meal as <30 g/meal (**a**) or <0.4 g/kg body mass/meal (**b**). Bars represent the percentage of inadequate protein intake per meal; whiskers represent 95% confidence intervals. *p*-values and ϕ statistic are for comparisons among countries within meals (χ<sup>2</sup> test of independence). Bars not sharing a similar letter (a, b, c, d) denote significant differences (*p* ≤ 0.05) among countries within meals (*t*-test for proportions with Bonferroni correction). U.K.: United Kingdom; U.S.A.: United States of America. Detailed data can be found in Table S3.

#### *3.5. Number of Meals per Day with Adequate Protein Content*

When the ≥30 g protein/meal criterion was used, Mexico (61.0%) and Germany (60.8%) showed the highest percentages of 0M (50% difference vs. U.K., small effect), U.K. (76.3%) showed the highest percentage of 1M (48% difference vs. Germany, small effect), whereas U.S.A. (14.5%) showed the highest percentage of +2M (10% difference vs. Mexico, small effect) (Figure 3a). The pattern was similar when comparisons were separated by sex, except there were no significant differences among countries for +2M for either sex (Figure S3a,b).

**Figure 3.** The number of meals per day containing ≥30 g protein (**a**) or ≥0.4 g protein/kg body mass (**b**) compared among countries. Bars represent the percentage of participants that reported the number of meals per day (zero, one, and two or three) with the mentioned protein content; whiskers represent 95% confidence intervals. *p*-values and ϕ statistic are for comparisons among countries within the number of meals (χ<sup>2</sup> test of independence). Bars not sharing a similar letter (a, b, c) denote significant differences (*p* ≤ 0.05) among countries within the number of meals (*t*-test for proportions with Bonferroni correction). U.K.: United Kingdom; U.S.A.: United States of America. Detailed data can be found in Table S3.

When the ≥0.4 g protein/kg/meal criterion was used, Germany (57.7%) and U.S.A. (48.5%) showed the highest percentages of 0M (50% difference vs. U.K., small effect), whereas U.K. (73.7%) showed the highest percentage of 1M (42% difference vs. Germany, small effect). In contrast, Mexico (19.8%) showed the highest percentage of +2M (10% difference vs. U.S.A., small effect) (Figure 3b). The comparisons separated by sex showed a different pattern to that observed in the whole sample. In women, there were significant differences among countries for 0M and 1M, but not for +2M groups (Figure S3c). In men, there were significant differences among countries for 0M, but not for 1M and +2M groups (Figure S3d).

#### *3.6. IPI Combined Results*

When data from the four samples were combined (*n* = 522), we calculated the percentage of IPID-0.8, IPID-1.0, IPID-1.2, IPIM-30, IPIM-0.4, and the number of meals with an adequate protein content (Table 3). Briefly, we observed that there was about a 20% increase in the percentage of IPI per day every time when the cut point was increased. For both IPIM-30 and IPIM-0.4, breakfast was the meal with the highest percentage, followed by dinner and lunch. For both ≥30 g/meal and ≥0.4 g/kg/meal criteria, eating 0M was the most condition, followed by 1M and +2M.


**Table 3.** Combined data (*n* = 522) from the four samples analyzed.

95% CI: 95% confidence intervals; IPID-0.8: inadequate protein intake per day (<0.8 g/kg/d); IPID-1.0: inadequate protein intake per day (<1.0 g/kg/d); IPID-1.2: inadequate protein intake per day (<1.2 g/kg/d); IPIM-30: inadequate protein intake per meal (<30 g/meal); IPIM-0.4: inadequate protein intake per meal (<0.4 g/kg/meal).
