Influence of Urban Green Space and Facility Accessibility on Exercise and Healthy Diet in Hong Kong

Round 1

Reviewer 1 Report

In "Materials and Methods", lines 104 and 105, it reads: "Adult residents aged at least 20 years and had been living in any of the nine districts for more than one year were the target population", there is no information if the study covered both genders. On the other hand, in Table 1 there is only information about the masculine gender.

 

In "Materials and Methods", lines 126 and 127, it reads: "Participants were asked on number of days in the past 7 days prior to the survey and daily time performing walking (as low-intensity), moderate and vigorous activities". There is no information if walking was intended for leisure-time physical activity or for commuting to work or other tasks.

 

The Table 1 presents a significant statistical difference between the "green cover levels" and different variables investigated, in such a way that it can have implication in the final result. For example, it was found that the high level of "green cover" showed higher mean values for MET-minutes / week. However, this group consisted of a larger number of low-income and educated people. How much did this impact the results? Perhaps, it would be interesting to perform a multivariate statistic.

Author Response

As attached.

Author Response File: Author Response.pdf

Reviewer 2 Report

General comments:

Thank you for the opportunity for reviewing this paper. This study assessed associations of green space with physical activity and dietary habits in Hong Kong. The findings presented in this study can contribute to the journal. However, there are major issues that I have with this manuscript:

1.       Abstract

2.       The aims of this study are unclear

3.       A lack of information in the Materials and Methods

4.       Discussion

 

1.       Abstract

The current abstract doesn’t include important information from the main manuscript. For example, this study does not ‘population-based cross-sectional study’, but used a ‘convenience sampling method’. Dietary habits wasn’t included in the aim but public open space.

Other key points such as:

·       Measurement of green space (how green space was measured: e.g., 500m around a participant’s residence)

·       How physical activity levels were calculated (IPAQ-C and MET)

 

2.       The aims of this study are unclear

The aims of this study were:

·       A population-based survey was conducted to understand the relationships between green cover and healthy lifestyle, particularly in physical activity levels and dietary habits in the nice urban residential areas of Hong Kong.

·       The usage of common facilities accessible to the residents and their characteristics would also be explored.

Based on the first aim, dietary habits should be included in the aim of the Abstract. In addition, the Introduction doesn’t provide enough information on the relationships between green space and dietary habits.

Public open space should be clearly stated in the aim (rather than ‘common facilities’).

 

3.       A lack of information in the Materials and Methods

Additional information is required in the Methods section. For example, how green space was measured.

 

4.       Discussion

The discussion section can be improved. For example, dietary habits were not discussed enough even though it was included in the study aim.

 

[Title]

“Promoting exercise in urban area: Importance of green space and facility accessibility”

The current title doesn’t include ‘dietary habits’ or a relevant phrase? Based on the study aims, dietary behaviour is one of the key topic?

[Abstract]

Background	‘Green space’ rather than ‘green cover’ (consistent use of the term   in the paper) ‘Physical activity’ rather than ‘physical activeness’
Methods	Please explain how green space was calculated. Please include how physical activity was measured. Please include how public open spaces were measured.
Results	‘younger groups’ – please indicate which age group.

 

[Introduction]

In general, the structure of the Introduction can be improved. For example, (1) how physical activity and healthy eating lifestyle can contribute to obesity and other chronic disease; (2) physical activity level in Hong Kong; (3) dietary habits in Hong Kong; (4) Importance of green space and public open space (please define both terms, particularly ‘public open space’), and its associations with physical activity and dietary habits – identifying research gaps; and (5) the aims of this study.

Lines 34-35	This sentence is slightly a repetition of lines 56-58. Possibly   combined these sentences together. Obesity can be mentioned in the beginning   of the Introduction.
Line 35	“The World Health Organization (WHO) recommended…”
Lines 40-41	“…who did no sport or exercise over a month” can be reworded to “and   did not involve any sports or exercise over a month”
Lines 42-44	Please remove ‘specifically’ (because it does not make sense).   Furthermore, the information listed in lines 39-46 can be summarised.   Currently it’s hard to get the key messages.
Line 44	Please change the word ‘despite’ (used as a preposition) to ‘although   or though’.
Lines 47-48	What does it mean by “protective effects”? Please clearly explain the   meaning of “adjusted odds ratios of 0.63 for men and 0.75 for women” for   readers (what do these values mean)?
Line 49	“(i.e., less than 600 MET-minus per week)” -> Please add the word   ‘total’ here.
Line 53	Please start a new paragraph from “Besides physical activity…”
Line 56	Please change ‘tael’ to ‘grams’ (or other universal units).
Lines 62-63	What does it mean by “such developed”?
Lines 63-64	“Additional contributing factors for obesity…” It is not sure this is   necessary. Does this link to QoL? If not, please remove this.
Lines 64-66	“Whilst people…” Please complete the sentence.
Line 69	“Obesity-related health indicators” – For example?
Lines 68-70	“... inconsistent and mixed evidence …; however, … controversial.” These   sentences are not contradicted. Please change ‘however’ to ‘similarly/likewise’.
Line 71	“in Netherlands” -> ‘in the Netherlands’
Lines 70-72	“A study conducted … green space.” Please paraphrase this sentence.
Lines 72-75	Please paraphrase/simplify this sentence (e.g., what does it mean by ‘multilevel   analysis’? This sentence is confusing.
Lines 77-79	It is not clear which definition (or both?) of green space was used in   this study?
Line 81	Please start a new paragraph from “Hong Kong is…”
Line 83	Please change the word ‘despite’ to ‘although/though’
Lines 84-85	“… most of these are woodland and shrub land located at the countryside   that are inaccessible to urban residents” Does it mean ‘woodland and shrub   land’ can be categorised as definition #1 (i.e., bodies of water or areas of   vegetation in a landscape)? And the definition of green space in this study   is #2 (i.e., urban vegetation that is relating to vegetated variant of open space)?
Line 88	Please define the term ‘open space’.
Lines 88-92	“Our recent QoL…” This sentence is too long. Please break it into two   sentences.
Lines 96-97	“The usage of common facilities” -> recreational facilities?

[Materials and Methods]

Line 102	“Old urban”?
Line 108	“Resting areas”?
Line 120	“First, the socio-demographic profiles of the residents were assessed”   -> The word ‘provided’ may be more appropriate than “assessed”.
Line 126	“7” -> ‘seven’
Line 128	“MER” -> ‘MET’
Line 129	“…based on the scoring guidelines” Please provide a brief explanation   of the guidelines or a reference to support this statement.
Lines 129-130	“Individuals who failed to answer all items of the IPAQ-C were   removed from the analysis.” This sentence can be move to the next section ‘2.1.   Data processing and analysis’. Also please provide the number of participants   excluded because of this reason.
Lines 132-133	This sentence can be moved to the Introduction section.
Lines 135-137	Please provide which software(s) and data source(s) were used to   calculate green space (e.g., GIS).
Line 137	The term ‘green space’ may be more appropriate than ‘green cover’.   Please use the term consistently across the manuscript.
Lines 141-142	A repetition from lines 137-139
Lines 143-144	Descriptive statistics also include continuous variables in addition   to categorical variables?
Table 1	Please change the legend to be more appropriate and informative. Please include Chi-square values for age, gender, marital status,   housing type, living status, educational level (also please correct p value   to ‘p<0.001’). Please use a footnote effectively (e.g., abbreviations (HKD, WHOQOL,   ANOVA etc.) and symbol (†))

[Results]

Lines 152-155	‘between’ rather than ‘among’?
Lines 155-159	“whose ages were evenly distributed” The youngest group (<25) was   only 13.91%, compared to the other age groups (which are between 27-31%).
Line 165	3 -> three
Line 170	4 -> four
Table 2	The format of this table can be improved (e.g., the centre alignment   of Mean±SD   and Frequency (Percentage), Chi-square test). Please use a footnote   effectively here too.
Lines 191-192	“Whilst…” This is an incomplete sentence.
Lines 194-197	This is not consistent with the study aim (particularly ‘only   participants with high and moderate IPAQ levels’).
Tables 4 and 5	It may be more logical to swap the order of Tables 4 and 5. Please   include footnotes for both tables.

[Discussion]

Lines 232-233	“In linear relationships” This is not accurate (r = 0.077 and 0.092)?
Lines 233-236	Too many information in one sentence. Please simplify the sentence,   or break it into two sentences.
Line 241	“Compact living environment”?
Line 243	“Built-up urban areas”?
Lines 243-244	Is this statement from the current study?
Lines 246-248	Please paragraph this sentence.
Line 248	What “this” indicates?
Lines 253-255	Please expand this sentence more – what kind of ‘behavioural changes’   happened.
Line 262	“Not uncommon” -> common?
Lines 263-265	“On the other hand…” This sentence doesn’t link with the previous   sentence.
Lines 267-269	“…will be discussed elsewhere” Does it mean ‘future studies’?
Line 274	Activeness -> activity
Line 273	“Whilst…” Please complete this sentence.
Lines 280	“Built-environment” -> “built environment”
Lines 284-285	“(The) current study identified parks within district as the main   pubic open spaces used by the residents” -> ‘recreational facilities’   rather than ‘public open spaces’. As mentioned, the definition of ‘open space’   is required in this paper.
Lines 289-290	There are other limitations of this study such as a convenience   sampling method and a geographical area which was limited to 500m around an   individual residence. Please acknowledge these limitations too.

 

[Conclusions]

The conclusions do not match with the aims of this study (e.g., dietary habits were left out). In addition, the term ‘public open spaces’ was used instead of ‘(recreational) facilities’. Please use the terms consistently (and define ‘open spaces’ appropriately).

Author Response

As attached.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The article has been improved dramatically. There are some minor changes required before publishing this article.

 

Another suggestion for the title of this article:

“Influence of urban green space and facility accessibility on exercise and healthy diet in Hong Kong”

 

Abstract:

1)      Background: A cross-sectional study using a convenience sampling method was 20 conducted to understand how green space and accessibility of common public open spaces in 21 compact urban areas affect physical activity and healthy diet of resident.

 

Introduction:

(Lines 44-47)

Physical activity and healthy eating are the two important aspects of healthy lifestyle [1-3]. A sedentary life together with excess energy intake particularly leads to the consequence of obesity, the major risk factor for mortality and many chronic problems including cardiovascular diseases [4;5], diabetes [6;7], and cancers [8;9].

 

(Lines 87-89)

The sentence may be changed to:

“This study adopted the former definition, and green space was measured using a vegetation dataset derived from the SPOT satellite images with the land use information in Hong Kong [28; 29].”

 

(Lines 91-93)

The sentence may be rephrased to:

“In this study, open space was categorised as urban green space according to the Hong Kong Planning Standards and Guidelines [23;30].”

(If you use the current sentence, it is not clear what are the other four categories of urban green space – except open space. If you would like to keep the sentence as it is, please include the other categories in the sentence.)

 

(Line 94)

Please change 7 to ‘seven’. (This is pedantic, but the other numbers have been now changed, and better to be consistent).

 

(Line 154)

“…derived from the SPOT satellite image…”

 

(Lines 155-159)

Please remove the phrase “Following a common approach that has been used for other research for built environment and health in Hong Kong [38;39]”, and change the sentence to:

“Addresses of all participants were geocoded to the HK 1980 grid coordinates, and the focal statistics of ArcGIS 10.6 was applied to calculate the percentage of green space within a 500 m radius buffer around each participant’s residence.”

 

(Table 1)

As chi-square tests (χ²) are indicated together with ‘one-way ANOVA’ in the far right heading of Table 1 (‘χ² test or one-way ANOVA’), footnote for ‘determined by the χ² test’ is not necessary. Please remove the symbol (†) and its footnote.

 

(Table 2)

Table 2 is confusing, particularly the section of one-way ANOVA and chi-square tests. It is recommended to keep the same format as Table 1 (‘χ² test or one-way ANOVA’ as a heading), and add χ² values with p-values shown as ‘χ²=’. Please remove the line above ‘Dietary habits’.

 

(Line 208)

“r = 0.11-0.13”?

 

(Table 4)

Please change the β values of ‘0’ to the word ‘Reference’ for University in Education, ≥ 23001 in Income, and High in Green level.

 

(Table 5)

Please see my comment in Table 1 (please add chi-square values where necessary).

 

(Table 6)

Please indicate which values are referred to in Student’s t-tests and chi-square tests. I assume that they are all p-values? If so, please include ‘p =’ for all values.

Author Response

As attached.

Author Response File: Author Response.pdf