Professional dietary coaching within a group chat using a smartphone application for weight loss: a randomized controlled trial

Figures & data

Figure 1 Participant flowchart.

Abbreviation: ITT, intention-to-treat.

Table 1 Participant characteristics at baseline

Characteristics	Coaching group (n=75)	Control group (n=37)
Demographics and lifestyle
Female	1.3%	0.0%
Age, years	45.6 (10.2)	47.8 (9.3)
Sleeping ≥6 hours every day*	14.1%	15.2%
Current smoking*	46.5%	30.3%
Current alcohol drinking*	71.8%	72.7%
Anthropometrics
Height, cm	172.3 (5.9)	172.0 (5.5)
Weight, kg	83.1 (11.1)	83.5 (9.8)
Body mass index, kg/m^2	28.0 (3.3)	28.2 (3.0)
Waist circumference, cm	97.7 (9.1)	98.3 (7.5)
Blood pressure, mm Hg
Systolic	130.9 (13.2)	130.8 (14.9)
Diastolic	82.7 (12.1)	82.9 (11.3)
Blood biochemistry
Triglycerides, mg/dL	146.0 (126.5)	146.0 (94.0)
HDL cholesterol, mg/dL	52.1 (11.5)	52.4 (10.8)
LDL cholesterol, mg/dL	135.4 (31.2)	135.6 (34.3)
Glycated hemoglobin A1c, %	5.97 (0.81)	5.87 (0.65)
Obesogenic eating behavior*
Eating snacks ≥ once a week	71.8%	72.7%
Eating out ≥ once a week	94.4%	90.9%
Eating fast foods ≥ once a week	38.0%	33.3%
Eating confectioneries ≥ once a week	77.5%	87.9%
Drinking SSBs ≥ once a week	63.4%	63.6%
Eating until full	84.5%	93.9%
Binge eating	56.3%	54.5%

Notes: Data expressed as mean (standard deviation) unless specified. The triglyceride presented as median (interquartile range).

* Data available for 71 (94.7%) participants in the coaching group and 33 (89.1%) in the control group.

Abbreviations: HDL, high-density lipoprotein; LDL, low-density lipoprotein; SSBs, sugar-sweetened beverages.

Table 2 Intention-to-treat analyses for changes in the primary and secondary outcomes, and percent improvement for eating behaviors

Dependent variables	8-week changes or % of those improved			12-week changes
	Coaching group (n=75)	Control group (n=37)	P-values	Coaching group (n=75)	Control group (n=37)	P-values
Anthropometrics
Weight, kg	−1.4 (−2.0, −0.8)	−0.1 (−0.6, 0.4)	0.001	−1.4 (−2.1, −0.8)	−0.1 (−0.7, 0.6)	0.004
Waist circumference, cm	−1.9 (−2.8, −1.0)	−0.9 (−2.0, 0.3)	0.15	−2.8 (−3.6, −1.9)	−1.1 (−2.3, 0.2)	0.02
Blood pressure, mm Hg
Systolic	−4.0 (−6.6, −1.4)	−1.6 (−5.4, 2.2)	0.30	−1.9 (−4.4, 0.5)	1.2 (−2.6, 4.9)	0.17
Diastolic	−3.7 (−5.5, −1.9)	−1.7 (−4.7, 1.2)	0.25	−2.2 (−4.1, −0.4)	0.1 (−2.9, 3.1)	0.19
Blood biochemistry
Log triglycerides, mg/dL	−0.11 (−0.20, −0.02)	0.11 (−0.03, 0.26)	0.01	−0.05 (−0.15, 0.06)	0.15 (−0.03, 0.33)	0.06
HDL cholesterol, mg/dL	−1.1 (−2.6, 0.4)	−1.7 (−3.3, −0.1)	0.57	0.1 (−1.6, 1.7)	−0.1 (−2.7, 2.6)	0.94
LDL cholesterol, mg/dL	−4.0 (−8.4, 0.5)	0.2 (−6.7, 7.0)	0.31	−4.8 (−8.4, −1.2)	−3.5 (−10.8, 3.7)	0.75
Glycated hemoglobin A1c, %	−0.15 (−0.24, −0.06)	0.02 (−0.06, 0.10)	0.01	−0.11 (−0.21, −0.02)	0.01 (−0.06, 0.07)	0.04
Obesogenic eating behavior*
Eating snacks ≥ once a week	16.9%	6.1%	0.23	–	–
Eating out ≥ once a week	4.2%	3.0%	1.00	–	–
Eating fast foods ≥ once a week	19.7%	6.1%	0.13	–	–
Eating confectioneries ≥ once a week	8.5%	3.0%	0.54	–	–
Drinking SSBs ≥ once a week	14.1%	3.0%	0.17	–	–
Eating until full	14.1%	6.1%	0.39	–	–
Binge eating	23.9%	12.1%	0.26	–	–

Notes: Data expressed as mean (95% confidence interval) unless specified.

* The denominators were 71 in the coaching group and 33 in the control group.

Abbreviations: HDL, high-density lipoprotein; LDL, low-density lipoprotein; SSBs, sugar-sweetened beverages; –, not assessed.