1 Introduction
1. The impact of diet and physical activity on health
is complex and multi-faceted. The committee reviewed recent progress
in this area in order to make some recommendations for the next
Government. In the time remaining in this Parliament we have tried
to focus on a 'what works' approach based on existing evidence.
We are very grateful to the many organisations and individuals
who provided written and oral evidence to this inquiry. All the
evidence we received is published in full on our website.[1]
We would also like to thank our specialist adviser for this inquiry,
Professor Mike Kelly.
2. NHS England's Five Year Forward View sets
out the urgent need for "a radical upgrade in prevention
and public health." It states, for example, that "it
makes little sense that the NHS is now spending more on bariatric
surgery for obesity than on a national roll-out of intensive lifestyle
intervention programmes that were first shown to cut obesity and
prevent diabetes over a decade ago."[2]
3. This introductory chapter gives a brief overview
of the current situation and what is known about the impact of
diet and physical activity on health. The second chapter discusses
general principles and key responsibilities for tackling physical
activity and diet. Our report centres around two key messages:
— Physical
activity—needs
to be seen as a crucial health priority in its own right
— Diet
and obesity—it is time for a national
debate about how to make it easier for people to make healthier
diet and lifestyle choices.
The impact of physical activity
on health
4. Physical activity is described as body movement
that expends energy and raises the heart rate. Inactivity is classed
as less than 30 minutes of physical activity a week, and sedentary
time means time spent in low-energy postures, e.g. sitting or
lying.[3] Globally, physical
inactivity is the fourth leading risk factor for mortality (accounting
for 6% of deaths). This follows high blood pressure (13%), tobacco
use (9%) and high blood glucose (6%). Overweight and obesity are
responsible for 5% of global mortality.[4]
In the UK, physical inactivity directly contributes to one in
six deaths.[5] Evidence
suggests that sedentary
behaviour is independently bad for health.[6]
The Chief Medical Officer has published guidelines on physical
activity for different age groups and recommendations about limiting
sitting time have been added to these.[7]
5. Public Health England state that the percentage
of adults achieving recommended levels of physical activity has
increased in the last fifteen years from 32% to 43% among men,
and from 21% to 32% among women. In 2012, 21% of boys and 16%
of girls aged 5-15 years met the national physical activity target.[8]
The Active People Survey shows that 29% of people are currently
classed as "inactive"—i.e. they fail to complete
30 minutes of moderate physical activity each week.[9]
6. Professor Nick Wareham of the MRC Epidemiology
Unit and the Centre for Diet and Activity Research at the University
of Cambridge, echoing the report of the CMO in 2013, cautions
that these self-reported statistics on physical activity may be
an overestimate, noting that "adults and children tend to
overestimate how physically active they are, and we lack good
nationwide data about actual levels of physical activity":
Repeated cross-sectional surveys such as the
National Diet and Nutrition Survey and Health survey for England
provide information about behaviours. However, because this data
is self-reported, its quality and reliability can be poor…objective
accelerometer data suggest that only 6% of men and 4% of women
achieve recommended level Both adults and children overestimate
how physically active they are, and parents overestimate how active
their children are.[10]
7. While measurement differences limit direct comparisons
Everybody Active Every Day provides data showing that the
problem is worse in the UK than many other countries.[11]
8. Public Health England provides the following statistics
on physical activity:
· Walking
trips decreased by 30% between 1995 and 2013
· 64% of trips
are made by car, 22% are made on foot, and 2% are made by bike
· 39% of non-disabled
adults regularly take part in sport, compared to 18% of disabled
adults.[12]
9. As well as describing the negative effects of
inactivity on health, much of the written evidence we have received
details the positive impacts of physical activity in unequivocal
terms:
We know that regular physical activity helps
prevent and manage over 20 chronic conditions including coronary
heart disease, stroke, type 2 diabetes, cancer, obesity, mental
health problems and musculoskeletal conditions. In addition, evidence
shows that there is a link between physical activity and good
mental wellbeing. For example, exercise is moderately more effective
than therapy for reducing symptoms of depression. It may also
help people with generalised anxiety disorder, panic attacks and
stress disorders.[13]
10. The Ramblers note that "unsurprisingly,
physical activity has been described as a 'wonder drug'".[14]
The University of Bedfordshire state that "we know of no
single intervention with greater promise than physical exercise
to reduce the risk of virtually all chronic diseases simultaneously"[15],
and the Transport and Health Study Group put the positive argument
for physical activity in even stronger terms:
If physical activity were a drug then the range
of its benefits on mental well being, mental illness, heart disease,
obesity, diabetes and osteoporosis is such that no politician
would dare withhold those benefits from the public. At a time
when the NHS struggles to cope with the pressures of mental illness,
obesity and diabetes, it is financially irresponsible to fail
to promote physical activity.[16]
The impact of diet on health
Obesity and overweight
11. Overweight and obesity are commonly defined by
Body Mass Index (BMI) in adults with overweight being defined
as a BMI between 25 and 29.9 and obesity as a BMI of 30 or over.[17]
For children, these BMI standards require adjustments for age
and gender. Public Health England explain the importance of diet
to weight:
Excess weight gain results from an imbalance
between energy consumed and energy expended and PHE recognises
that eating less is crucial for weight loss. PHE estimates that
the average man and woman in England consume respectively approximately
300 and 200 calories a day more than they need. Alcohol consumption
is also linked to excess calorie intake and an emerging evidence
base suggests that it and obesity compound problems such as fatty
liver disease.[18]
12. Public Health England describe the negative health
impacts of obesity:
Being obese can increase the risk of developing
a range of serious diseases, including hypertension, type 2 diabetes,
cardiovascular diseases, several cancers, asthma, obstructive
sleep apnoea, and musculoskeletal problems.[19]
13. They also note that obese children are more likely
to be ill, absent from school, and suffer psychological problems
such as low self-esteem and depression than normal weight children.
14. Public Health England provide the following statistics
on the prevalence of obesity:
Obesity levels remain high with two-thirds of
the adult population, one in five 4-5 year olds and one in three
10-11 year olds in England [being] either overweight or obese.
In the last decade, the prevalence of adult obesity has risen
from 15% to 25%, whilst the prevalence of overweight has remained
broadly stable (37%-39%) during this period. In the last seven
years, the proportion of children aged 4-5 years who were obese
has remained broadly stable (9.9%-9.5%) whilst the proportion
of children aged 10-11 years who are obese has increased (17.5%-19.1%).
Obesity and related conditions vary according
to ethnic group, socioeconomic status and geography. Obesity disproportionately
affects those in the most deprived social groups and evidence
suggests that the inequalities gap in child obesity is widening.[20]
15. The Department of Health states that "the
rising levels of overweight and obesity we have seen over the
past 20 years or so appear to be stabilising, but at a very high
level."[21] There
is also recent evidence showing that the rates of morbid obesity
in children are increasing.[22]
Trend in obesity prevalence among adults
Adult (aged 16+) obesity: BMI = 30kg/m2
Source - Health Survey for England 1993-2013 (3-year
average)-Public Health England
Trend in excess weight among adults
Adult (aged 16+) overweight including obese: BMI
= 25kg/m2
[Source - Health Survey for England 1993-2013 (3-year
average)-Public Health England]
OTHER HEALTH IMPACTS OF DIET
16. The impact of diet on health is not limited to
its impact on weight. The Scientific Advisory Committee on Nutrition
(SACN) recommendations for intakes of energy, nutrients, and some
food groups are translated into nutrient and food based guidance
for populations. This underpins dietary advice as depicted in
the national food guide 'the eatwell plate' and the five-a-day
advice for fruit and vegetables.[23]
17. Commenting on current eating habits, Public Health
England state:
The population overall is consuming too much
saturated fat, non-milk extrinsic sugars (which includes added
sugars and free sugars in fruit juices) and salt and not enough
fibre, oily fish or fruit and vegetables. On average, no population
age group meets current dietary recommendations. The diets of
young children under four years are close to meeting recommendations
while the diets of adolescents (particularly girls) are the worst.
Some aspects of diet vary with income, for example fruit and vegetables,
fibre and some micronutrients show a clear pattern of lower intakes
in lower income groups. Over the last 10 years salt intakes of
adults have reduced by 15% but remain above the maximum recommended
level.
Current intakes of sugar for all population groups
exceed recommendations. Sugar increases the risk of tooth decay
and of consuming too many calories, which, if sustained, causes
weight gain and obesity.[24]
18. Consumption of food and drinks high in sugar
increases the risk of the development of type 2 diabetes.[25]
19. The UK Faculty of Public Health argues that "for
cardiovascular disease prevention, there is clear evidence that
the Mediterranean diet, even just a handful of nuts and or liberal
consumption of olive oil, is effective, and could lead to a rapid
30% reduction in deaths & non-fatal events. Furthermore, this
demonstrates that a healthy diet is more powerful than statins."[26]
In relation to children's eating habits, the Local Government
Association notes:
While the number of children eating the recommended
amounts of fruit and vegetables has increased in recent years,
80 per cent of children still do not eat the recommended '5-a-day'.
England's young people have the highest consumption of sugary
soft drinks in Europe.[27]
Physical activity—a priority
in its own right
20. One of the clearest messages the Committee has
heard during the course of this inquiry is that the considerable
health benefits of physical activity independent of weight must
be more clearly acknowledged and communicated. The Royal College
of Physicians told us:
Often the benefits of physical activity are closely
linked to reductions in obesity. The RCP however, strongly recommends
that wider benefits of physical activity should be recognised
and promoted. Individuals who are obese but have a good level
of cardiorespiratory fitness (CRF) can have better health and
wellbeing than an individual with an ideal body Mass Index (BMI)
but low CRF. The wider health benefits of physical fitness should
be promoted to improve the health of the nation.[28]
21. The written evidence received by the Committee
also suggests that while physical activity has benefits for all
people regardless of weight, and may help maintain weight loss,
"increasing physical activity…is unlikely to be the
best single strategy for combatting excess weight"[29].
The Department of Health agree, stating that "although physical
activity brings important health benefits…for those who are
overweight and obese, eating and drinking less is key to weight
loss".[30]
22. Research very recently published by the MRC drawing
on the EPIC (European Prospective Investigation into Cancer) study
reported that in terms of reducing mortality risk, for the most
inactive people, walking for around 20 minutes extra per day would
have a greater positive impact than not being obese,[31]
as Professor Nick Wareham explained:
About 23% of people in that study—and there
was a large group of people in that study from the United Kingdom—were
in the category of being totally inactive; they had a sedentary
job and did no recreational physical activity at all. That group
had the highest mortality risk. If you look at the difference
between that group and the moderately inactive, there was about
a 20% reduction in mortality risk. Switching from being totally
inactive to moderately inactive would require the equivalent of
walking 20 minutes extra per day, which is a totally feasible
public health transition. We estimated that, if everybody who
was in that totally inactive category could move up to the next
category, the impact on mortality would be of the order of 7%.
That was greater than the impact of the avoidance of obesity.
The important thing for the Committee is that that impact of physical
activity was independent of obesity. So within the strata of whether
someone is obese, overweight or a normal weight, the effect of
physical activity was the same.[32]
23. Dr William Bird, a GP with an interest in physical
activity and founder of Intelligent Health, reinforced this point:
We have finally got the evidence to disentangle
the connection between obesity and physical activity. I am grateful
for obesity getting physical activity on the agenda because that
has been the way it has managed to get up on to the podium, but
we must not use weight loss as a measure of success for physical
activity. Physical activity has always been the handmaiden of
obesity—the way you have diet and physical activity for
the objective of losing weight. That is no longer evidence based
and should not be used again. Of course obesity is important,
but physical activity in its own right has benefits. In fact only
10% of the benefits of physical activity for cardiovascular disease
are weight-related. The other 90% are the anti-inflammatory effects—the
other aspects of cellular change that take place when you are
physically active.[33]
He went on to give the startling example that
Giving a coronary stent to patients with stable
angina or getting them to exercise for 20 minutes a day have exactly
the same outcomes after one year, except that exercise is more
effective.[34]
24. Professor Dame Sue Bailey, Chair of the Academy
of Medical Royal Colleges, gave two further compelling examples
of the impact of exercise on health—firstly that exercise
can be beneficial for treating childhood depression, and should
be used tried as a first line treatment, together with psychological
therapies, before using drug treatments; and secondly that exercise
is effective in strengthening bone density to prevent fractures
in older people. In all of these examples exercise would be a
far cheaper option. Professor Dame Sue Bailey went on to say that
in her view it was "regrettable" that the evidence has
been there for some time and "neither the public, politicians
nor practitioners have gone with this sufficiently."[35]
The Academy of Medical Royal Colleges has recently published a
report entitled Exercise: the miracle cure and the role of
the doctor in promoting it, aimed at publicising the "simple"
message that "exercise is a miracle cure too often overlooked
by doctors and the people they care for":
The big four "proximate" causes of
preventable ill-health are: smoking, poor nutrition…physical
inactivity and alcohol excess. Of these, the importance of regular
exercise is the least well-known. Relatively low levels of increased
activity can make a huge difference. All the evidence suggests
small amounts of regular exercise (five times a week for 30 minutes
each time for adults) brings dramatic benefits. The exercise should
be moderate—enough to get a person slightly out of breath
and/or sweaty, and with an increased heart rate.
Doctors are increasingly being asked to carry
out a range of interventions when they see patients, including
screening and changing behaviour, with initiatives such as 'Make
Every Contact Count'. However this report calls on doctors to
promote the benefits of regular physical activity to their patients
and to communities in their wider roles as 'advocates for health'.
We have some tips, but the message is simple. Exercise is a miracle
cure too often overlooked by doctors and the people they care
for.[36]
25. For too long, physical activity
has been seen merely in the light of its benefits in tackling
obesity. However, there is compelling evidence that physical activity
in its own right has huge health benefits totally independent
of a person's weight—in fact research recently published
suggested that increasing physical activity levels could have
greater impact on reducing mortality than reducing weight. The
Chief Medical Officer's guidelines recommend levels of activity
which will help people derive the greatest health benefits; but
even small increases in activity levels can have a dramatic positive
impact on health.
26. Diet, obesity, and physical
activity all have important impacts on health. However, it is
vital that the importance of physical activity for all the population—regardless
of their weight, age, gender, health, or other factors—is
clearly articulated and understood. We recommend that the Government,
Public Health England and health professionals, in particular
GPs, to take urgent action to communicate this crucial message
to the public.
1 Health Select Committee, The Impact of physical activity and diet on health Back
2
NHS England Five Year Forward View (October 2014), p 9, p 11 Back
3
Public Health England, Everybody Active Every Day - an evidence based approach to physical activity
(October 2014), p4 Back
4
Department of Health, Start Active Stay Active (July 2011), p10 Back
5
Public Health England, Everybody Active Every Day - an evidence based approach to physical activity
(October 2014),p6 Back
6
Biddle, S., Pearson, N., Ross, G.M. Braithwait, R. (2010) Tracking
of sedentary behaviours of young people: a systematic review,
Preventive Medicine; 51: 345-51. Rezende et al. BMC Public Health
2014, 14:333 Sedentary behavior and health outcomes among older
adults: a systematic review; Int.J. Behav. Med. (2010) 17:243-245
Psychological Determinants and Outcomes of Sedentary and Physical
Activity Behaviours Yvette D. Miller Back
7
Public Health England, Everybody Active Every Day - an evidence based approach to physical activity
(October 2014),p22 Back
8
Public Health England (IDH0063) para 23 Back
9
HM Government, Moving More, Living More, 2014, para 2.2 Back
10
Centre for Diet and Activity Research (IDH0069) para 3.1 Back
11
Public Health England, Everybody Active Every Day - an evidence based approach to physical activity
(October 2014) p6 Back
12
Public Health England, Everybody Active Every Day - an evidence based approach to physical activity
(October 2014), p5 Back
13
Department of Health (IDH0078) para 14 Back
14
Ramblers (IDH0014) para 6 Back
15
University of Bedfordshire (IDH0029) para 4 Back
16
Transport and Health Study Group (IDH0048) p1 Back
17
BMI = m/h2, where m is mass in kilograms and h is height
in metres. Back
18
Public Health England (IDH0063) para 21 Back
19
Public Health England (IDH0063) para 15 Back
20
Public Health England (IDH0063) paras 12-13 Back
21
Department of Health (IDH0078) para 16 Back
22
Ells, L.J., Hancock, C, Copley, V.R., Mead, E., Dinsdale, H.,
Kinra, S., Viner, R.M., Rutter, H. (2015) Prevalence of severe
childhood obesity in England: 2006-2013, Arch Dis Child doi:10.1136/archdischild-2014-307036
http://adc.bmj.com/content/early/2015/01/27/archdischild-2014-307036.full.pdf+html
Back
23
Public Health England (IDH0063) para 17 Back
24
Public Health England (IDH0063) para 18, para 20 Back
25
Further information can be found at http://www.nhs.uk/conditions/Diabetes-type2/Pages/Introduction.aspx
and http://www.diabetes.org.uk/ Back
26
UK Faculty of Public Health (IDH0083) p2 Back
27
Local Government Association (IDH0022) para 25 Back
28
Royal College of Physicians (IDH0043) para 2 Back
29
Centre for Diet and Activity Research (IDH0069), Executive Summary Back
30
Department of Health (IDH0078)
para 13 Back
31
Ekelund, U et al. Physical activity and all-cause mortality across
levels of overall and abdominal adiposity in European men and
women: the European Prospective Investigation into Cancer and
Nutrition Study (EPIC) American Journal of Clinical Nutrition;
doi: 10.3945/ajcn.114.100065 http://ajcn.nutrition.org/content/early/2015/01/14/ajcn.114.100065.abstract
Back
32
Q6 Back
33
Q283; for further information see Mora, S., Cook, N., Buring,
J. E., Ridker, P. M., & Lee, I. M. (2007). Physical activity
and reduced risk of cardiovascular events potential mediating
mechanisms. Circulation, 116(19), 2110-2118. Back
34
Q288 Back
35
Q295 Back
36
Academy of Medical Royal Colleges, Exercise: the miracle cure and the role of the doctor in promoting it
, (February 2015), p5 Back
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