From all screened articles, 51 unique interventions, which met the selection criteria, were included. The general characteristics of these interventions are summarised in Table 1.
As for the year of publication, we observe a peak of interventions published in 2016 (24%) that declines in the following years, although it seems to increase again in the last years, 2019 and 2021. Suppose we refer to the main topic of the journals in which the selected interventions are published. In that case, we find that most interventions are published in gynaecology (25%) and nutrition journals (28%), with only 8% being published in specific journals of childhood obesity or 10% in obesity journals.
Focusing on the geographical region in which the intervention takes place, it stands out that the majority of interventions (81%) take place in developed areas, such as the USA (33%), Australia/New Zealand (24%) and Europe/UK (24%). There are very few interventions in developing areas such as Africa (2%), South America (5%) or Central America (0%) or Asia (12%).
Table 1
General characteristics of childhood obesity prevention interventions published from 2016 to 2021 (n = 51)
|
|
n (%)
|
Publication Year
|
|
2016
|
12 (24)
|
2017
|
5 (10)
|
2018
|
8 (16)
|
2019
|
9 (18)
|
2020
|
7 (13)
|
2021
|
10 (19)
|
Topic of the Journal of publication
|
|
Nutrition
|
14 (28)
|
Obesity
|
5 (10)
|
Childhood obesity
|
4 (8)
|
Gynaecology
|
13 (25)
|
Medicine
|
10 (19)
|
Paediatrics
|
5 (10)
|
Geographic region
|
|
Europe/United Kingdom
|
12 (24)
|
United States
|
17 (33)
|
Australia/New Zealand
|
12 (24)
|
South America
|
3 (5)
|
Asia
|
6 (12)
|
Africa
|
1 (2)
|
Targeted population
|
|
General population
|
44 (86)
|
Racial/ethnic groups
|
6 (12)
|
Low-income groups
|
1 (2)
|
Setting
|
|
Community-based
|
16 (31)
|
Health care
|
35 (69)
|
Mode of delivery
|
|
In-person
|
31 (61)
|
Using technology
|
2 (4)
|
Both
|
18 (35)
|
In terms of the target population of these interventions, almost all (86%) are targeted at the general population, with very few interventions specifically targeting ethnic or racial groups (12%) or the lower-income population (2%).
It is only in the USA that interventions targeting racial or ethnic groups are developed, specifically 33% of all interventions developed in this country. On the other hand, in South America, the only intervention aimed at the lower-income population has been developed.
In terms of the setting of the interventions included in this review, we found that most interventions (69%) have been developed in health care settings.
Finally, most interventions continue to be carried out face-to-face (61%). However, there is a growing tendency to use technology in combination with face-to-face development of interventions (35%).
The characteristics of the interventions are summarised in Table 2.
Table 2
Intervention characteristics of childhood obesity prevention interventions published from 2016 to 2021 (n = 51)
|
|
n (%)
|
Start of the intervention
|
|
First trimester
|
14 (28)
|
Second trimester
|
28 (54)
|
Third trimester
|
4 (8)
|
Postpartum
|
5 (10)
|
End of the intervention
|
|
During pregnancy
|
5 (10)
|
At birth
|
31 (61)
|
During the first year
|
6 (12)
|
At first year
|
4 (8)
|
At second year
|
2 (4)
|
> 2 years
|
3 (5)
|
Included mothers
|
|
All pregnant
|
22 (44)
|
Normal weight
|
5 (10)
|
With obesity and overweight
|
15 (29)
|
With obesity
|
6 (12)
|
With clinic antecedents
|
3 (5)
|
Targeted issue
|
|
Gestational weight gain
|
13 (25)
|
Gestational Diabetes Mellitus
|
3 (5)
|
Pregnancy outcomes
|
11 (22)
|
Children nutritional status
|
24 (48)
|
Type of interventiona
|
|
Nutrition
|
8 (16)
|
Physical Activity
|
11 (22)
|
Nutrition and Physical Activity
|
17 (33)
|
Lifestyle (including breastfeeding)
|
13 (25)
|
Lifestyle (including sleep)
|
3 (5)
|
Use of supplements
|
2 (4)
|
Main outcomes
|
|
GWG
|
18 (36)
|
GDM
|
10 (19)
|
Breastfeeding
|
6 (12)
|
Measures of children
|
14 (28)
|
Pregnancy outcomes
|
3 (5)
|
Measures of children
|
|
Birthweight
|
35 (68)
|
Body mass index (BMI)
|
8 (16)
|
Skinfolds
|
8 (16)
|
Moment of children measures
|
|
Birth
|
30 (59)
|
During the first year
|
10 (19)
|
Birth to 2 years
|
4 (8)
|
> 2 years
|
7 (14)
|
a Groups are not mutually exclusive thus, totals may exceed 100%.
In terms of the time these interventions begin, all of the interventions included in the review begin during pregnancy. Specifically, the majority (54%) start in the second trimester of pregnancy, i.e. from the 14th week. Only 28% of the interventions start before this time, during the first trimester.
There are more differences in the timing of the end of the interventions. A clear majority (61%) end at the time of birth. Of the remainder, 10% end before pregnancy comes to an end, while 12% end at different times during the first year of life. 8% of interventions continue into the second year of life and end at some point during the second year of life, while only 4% end at the age of two years. On the other hand, only 5% of the interventions continue after the second year of life.
Regarding the group of women targeted by the intervention, in terms of their nutritional status at the start of pregnancy, 44% of the interventions include all pregnant women. In comparison, 29% include only those with overweight, i.e. with overweight or obesity. 12% of the interventions target only women with obesity, and 10% target only women with average weight. Finally, 5% of the interventions target mothers with a medical history of gestational diabetes, a newborn with macrosomia or some other complication of pregnancy.
We find different categories if we analyse the issue on which the interventions are focused. Only 48% of these interventions are focused on improving the nutritional status of the offspring in the short term. 25% focus on controlling the weight gain of pregnant women during this period in order to avoid excessive weight gain. 22% of interventions aim to improve pregnancy outcomes, while 5% focus on preventing the development of gestational diabetes mellitus.
Regarding the type of intervention, most interventions are nutritional and physical activity at the same time (33%). While 25% address lifestyle to improve health, including breastfeeding, only 5% also include rest as a determining factor.
In terms of the main variables collected, there are many interventions whose main outcome measure is excessive weight gain (36%). The rest focus on collecting the development of gestational diabetes mellitus (19%), initiation of breastfeeding (12%), anthropometric measures in offspring (28%) or pregnancy outcomes in general (5%).
Most interventions collect the baby's weight at birth (68%). Only 16% take BMI measurements, which is valid for skinfolds. As for the timing of these measurements, 19% take them at different times during the first year of life, only 8% of the interventions take them at two years of age, while 14% take them after this age.
Table 3 represents a cross-tabulation of the mothers included, the type of intervention, the main variables, the variables collected from the baby and the time of collection of these variables according to the aspect addressed.
Table 3
Included mothers, type of intervention, main outcomes, children's measures and moment of collection depending on the targeted issue (n=51)
|
|
Targeted issue
|
n (%)
|
GWG + GDM
|
Pregnancy outcomes
|
Children nutritional status
|
Included mothers
|
|
|
|
All pregnant
|
8 (50)
|
5 (45)
|
10 (42)
|
Normal weight
|
1 (6)
|
3 (28)
|
0 (0)
|
With obesity and overweight
|
5 (32)
|
1 (9)
|
9 (38)
|
With obesity
|
1 (6)
|
2 (18)
|
3 (12)
|
With clinic antecedents
|
1 (6)
|
0 (0)
|
2 (8)
|
Type of intervention
|
|
|
|
Nutrition
|
3 (19)
|
0 (0)
|
5 (21)
|
Physical Activity
|
5 (32)
|
3 (28)
|
3 (12)
|
Nutrition and Physical Activity
|
7 (43)
|
6 (54)
|
4 (17)
|
Lifestyle (including breastfeeding/sleep)
|
1 (6)
|
2 (18)
|
10 (42)
|
Use of supplements
|
0 (0)
|
0 (0)
|
2 (8)
|
Main outcomesa
|
|
|
|
GWG
|
16 (100)
|
5 (45)
|
4 (17)
|
GDM
|
9 (56)
|
7 (63)
|
0 (0)
|
Breastfeeding
|
0 (0)
|
2 (18)
|
4 (17)
|
Measures of children
|
0 (0)
|
5 (46)
|
13 (54)
|
Pregnancy outcomes
|
0 (0)
|
3 (28)
|
3 (12)
|
Measures of children
|
|
|
|
Birthweight
|
14 (88)
|
6 (55)
|
8 (33)
|
Body mass index (BMI)
|
2 (12)
|
1 (9)
|
11 (46)
|
Skinfolds
|
0 (0)
|
4 (36)
|
5 (21)
|
Moment of children measures
|
|
|
|
Birth
|
14 (88)
|
7 (63)
|
9 (38)
|
During the first year
|
1 (6)
|
3 (28)
|
6 (25)
|
Birth to 2 years
|
0 (0)
|
1 (9)
|
3 (12)
|
> 2 years
|
1 (6)
|
0 (0)
|
6 (25)
|
a Groups are not mutually exclusive thus, totals may exceed 100%.
It is observed that those interventions that focus on controlling GWG or GDM include mostly (50%) all types of women in terms of nutritional status. However, a high percentage (32%) include only those women with excess weight. They are mainly interventions that combine nutrition and physical activity as tools (43%). Finally, they are interventions that mainly collect the GWG of mothers (100%) and the birth weight of offspring (88%).
Interventions that aim to improve pregnancy outcomes generally are more diverse in terms of the nutritional status of the mothers included, although the majority (45%) include all types of women. 54% of these interventions address nutrition and physical activity together. As for the collection of variables, there is diversity among the interventions, finding those that collect GWG, GDM, different measures in the offspring or at the end of pregnancy.
Finally, interventions focused on improving the nutritional status of offspring mainly include all mothers (42%), but remains high the interventions that only include those mothers who have obesity or overweight (38%). They improve overall lifestyle, including breastfeeding or sleep, to achieve their goals (42%). Most of these interventions collect measures of offspring at birth (38%). These measures include skinfolds and BMI, as well as birth weight.
Figure 2 shows the type of developed interventions, depending on the targeted issue. It highlights how most interventions focus on nutrition or physical activity while only those that focus on improving the nutritional status of offspring cover lifestyle in general.