An increase in the incidence of metabolic diseases has highlighted the importance of many amino acids especially lysine that has the capacity to alter the body composition offering a protective role for the diseases.
Protein And Lysine Intakes
The mean total protein intake of Group I (39.22 g) was almost similar to the protein intake of Group II (40.39 g) as shown in Table 1. The total lysine intake of the subjects in Group II was significantly (p ≤ 0.05) higher (1024.82 mg) in comparison to Group I (956.45 mg). When the intakes were compared with the recommended dietary allowances, the average protein intake was 71.88% of the recommended value of 55 g/day[9] but the mean total lysine intake was only 39.41% of the recommended levels of 2475 mg/day[5]. On calculating, the lysine intake (mg) in different meals of the day on per gram protein basis, the diets were found to be deficient with an average amount of 24.67 mg lysine on per gram protein basis against the recommended level of 45 mg/g of protein[5].
Table 1
Average daily protein and lysine intake of selected young adult women
Meal
|
Group I
(n = 346)
|
Group II
(n = 127)
|
Overall
(n = 473)
|
Range
|
Mean ± SD
|
Range
|
Mean ± SD
|
Range
|
Mean ± SD
|
Protein(g)
|
Breakfast
|
1.26–24.69
|
11.31
± 4.18a
|
3.40-19.46
|
10.68
± 3.91a
|
1.26–24.69
|
11.14
± 4.12
|
Lunch
|
0-29.17
|
11.57
± 4.25a
|
0-21.88
|
11.98
± 3.79a
|
0-29.17
|
11.68
± 4.16
|
Dinner
|
1.56–22.48
|
10.12
± 3.28a
|
1.92–20.37
|
9.88
± 3.34a
|
1.56–22.48
|
10.06
± 3.29
|
Mid-morning
|
0-8.93
|
1.48
± 1.87a
|
0-15.68
|
1.97
± 2.64b
|
0-15.68
|
1.61
± 2.12
|
Evening time
|
0-18.21
|
4.74
± 3.11a
|
0-18.87
|
5.88
± 3.57b
|
0-18.87
|
5.04
± 3.28
|
Total
|
17.91–60.47
|
39.22
± 7.73a
|
20.70-60.38
|
40.39
± 8.46a
|
17.91–60.47
|
39.53
± 7.94
|
Lysine(mg)
|
Breakfast
|
29.84-719.29
|
243.34 ± 131.50a
|
58.01-551.06
|
243.02 ± 135.79a
|
29.84-719.29
|
243.77 ± 132.19
|
Lunch
|
0-958.97
|
345.18 ± 148.51a
|
0-792.62
|
374.26 ± 153.33a
|
0-958.97
|
352.99 ± 150.21
|
Dinner
|
17.49-870.38
|
315.60
± 144.21a
|
75.45–738.90
|
308.61 ± 127.94a
|
17.49-870.38
|
313.72 ± 139.93
|
Mid-morning
|
0-174.30
|
7.43
± 24.45a
|
0-772.49
|
20.21
± 98.02b
|
0-772.49
|
10.86 ± 55.08
|
Evening time
|
0-555.12
|
44.90
± 74.72a
|
0-669.60
|
78.72
± 125.19b
|
0-669.60
|
53.98 ± 92.14
|
Total
|
308.28-1748.48
|
956.45
± 252.51a
|
413.47–2103.00
|
1024.82
± 287.01b
|
308.28–2103.00
|
975.32
± 263.66
|
Values in columns followed by different superscripts differ significantly (p ≤ 0.05) |
Table 2
Body composition parameters of selected young adult women
Body composition parameters
|
Group I
(n = 346)
|
Group II
(n = 127)
|
Overall
(n = 473)
|
Range
|
Mean ± SD
|
Range
|
Mean ± SD
|
Range
|
Mean ± SD
|
Height, cm
|
144.50-175.50
|
158.59 ± 5.46a
|
147.00-169.50
|
157.48 ± 4.81b
|
144.50-175.50
|
158.29 ± 5.31
|
Weight, Kg
|
38.30–56.20
|
58.10 ± 3.63a
|
41.00-85.10
|
58.79 ± 9.29a
|
38.30–85.10
|
58.60 ± 4.22
|
|
Fat Mass (Kg)
|
1.2–40
|
13.81 ± 6.89a
|
3-34.1
|
15.62 ± 6.55b
|
1.2–40
|
14.30 ± 6.84
|
Fat Mass (%)
|
3-45.8
|
23.70 ± 7.97a
|
7.2–40.1
|
25.88 ± 6.80b
|
3-45.8
|
24.29 ± 0.73
|
Fat Mass Index (Kg/m2)
|
0.44–17.29
|
5.49 ± 2.72a
|
1.14–13.49
|
6.28 ± 2.58b
|
0.44–17.29
|
5.70 ± 2.71
|
Visceral Fat Rating
|
1–9
|
1.72 ± 1.35a
|
1–7
|
2.26 ± 1.54b
|
1–9
|
1.86 ± 1.42
|
Muscle Mass (Kg)
|
32.4–51.7
|
40.44 ± 4.14a
|
32.4–52.9
|
39.78 ± 3.29a
|
32.4–52.9
|
39.96 ± 3.55
|
Muscle Mass (%)
|
6.74–98.28
|
72.18 ± 10.04a
|
48.94–95.21
|
70.55 ± 8.21a
|
6.74–98.28
|
71.74 ± 9.60
|
Skeletal Muscle Mass (Kg)
|
14.03–94.77
|
21.41 ± 5.20a
|
13.19–92.56
|
21.06 ± 9.66a
|
13.19–94.77
|
21.32 ± 7.78
|
Muscle mass Index (Kg/m2)
|
5.74–37.66
|
8.53 ± 10.40a
|
5.60-37.31
|
8.49 ± 3.87a
|
5.60-37.66
|
8.51 ± 3.17
|
Fat Free Mass (Kg)
|
18.8–54.5
|
42.14 ± 5.20a
|
18.8–55.7
|
41.74 ± 3.85a
|
18.8–55.7
|
41.85 ± 4.25
|
Fat Free Mass (%)
|
7.09–97.43
|
75.72 ± 10.94a
|
30.17–96.37
|
73.58 ± 10.25a
|
7.09–97.43
|
75.17 ± 10.78
|
Fat Free Mass Index (Kg/m2)
|
8.03–21.34
|
17.01 ± 2.08a
|
7.03–22.39
|
16.62 ± 1.60a
|
7.03–22.39
|
16.73 ± 1.75
|
Values in columns followed by different superscripts differ significantly (p ≤ 0.05) |
Body Composition Parameters
The average percent body fat mass of the subjects in Group I and II was 23.70 and 25.88%, respectively. A significantly (p ≤ 0.05) higher fat mass was observed among the subjects in Group II in comparison to Group I. The mean fat mass index values of the subjects in Group I and Group II was 5.49 and 6.28 kg/m2, respectively, the values of group I were close to the cut off value of 5.5 but the subjects in Group II had average fat mass index above this cut-off [11]. A significantly (p ≤ 0.05) lower fat mass index of the subjects in Group I was observed when compared to Group II. Moreover, the excess body fat was found among 50 and 60% of the subjects in Group I and II, respectively (Fig. 1). A significant (p ≤ 0.05) increase in visceral fat rating of the subjects was observed with the advancement of age. The total muscle mass and skeletal muscle mass of the subjects in Group I was 40.44 and 21.41 kg, respectively, the corresponding values for the subjects in Group II were 39.78 and 21.06 kg. On the other hand, the average values of fat free mass in both the groups were 42.14 and 41.74 kg, the percent fat free mass being 75.72 and 73.58%, respectively. The fat free mass index of the subjects in Group I and II was 17.01 and 16.62 whereas, the muscle mass index calculated from skeletal muscle mass values was 8.53 and 8.49 for Group I and II, respectively. Thirty and 17% of the subjects had muscle mass index and fat free mass index lesser than the respective cut off values of 15.4[11] and 7.6[12] hence, possessed lesser muscle mass as depicted in Figs. 2 and 3.
Associations Between Lysine Intakes And Body Composition
The statistical analysis using Pearson’s Correlation Coefficient (Table 3) showed that protein intake of the subjects was negatively and significantly (p ≤ 0.05, 0.01) correlated with the parameters of general obesity (BMI) and abdominal obesity (Waist circumference). Further, higher intake of protein was positively and significantly (p ≤ 0.05, 0.01) correlated with muscle mass percent, muscle mass index and fat free mass index, hence, associated with enhanced muscle mass. Similarly, higher lysine intakes were associated with lower obesity as lysine intake was found to be negatively and significantly (p ≤ 0.05, 0.01) correlated with body weight, body mass index, waist circumference, waist and hip ratio and fat mass index. Lysine intake was also found to be positively and significantly (p ≤ 0.05, 0.01) correlated with percent muscle mass, muscle mass index and fat free mass index thereby, proved that lysine inadequacy is associated with poor muscle mass.
Table 3
Correlation Coefficients (r) among nutrients, anthropometry and body composition parameters
Parameter
|
Protein
|
Lysine
|
Body weight
|
-
|
-0.135*
|
Body Mass Index
|
0.325**
|
-0.231**
|
Waist Circumference
|
0.152*
|
-0.251**
|
Waist and Hip Ratio
|
-
|
-0.154*
|
Fat Mass Index
|
-
|
-0.278**
|
Muscle Mass%
|
0.318**
|
0.314**
|
Muscle mass Index
|
0.210**
|
0.221**
|
Fat free mass Index
|
0.382*
|
0.371*
|
*p ≤ 0.05; **p ≤ 0.01 |