Page 892 - Cardiac Nursing

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868 PA R T V / Health Promotion and Disease Prevention
Low-carbohydrate diets have received considerable attention in strength two times per week (8 to 10 exercises using a resistance
recent years by the lay public and the scientific community. 62,63 weight allowing for 8 to 12 repetitions per exercise). For adults
One of the biggest concerns about the low-carbohydrate diet, which older than 65 years it is important for the health care provider to
is accompanied by a high fat and high protein intake, is its effects instruct them to use ratings of perceived exertion to monitor their
on coronary risk factors. However, the studies that have been con- activity level. Older adults should not engage in exercise that is
ducted to evaluate this dietary approach to weight loss have found too vigorous for their age or the presence of potential comorbid
both benefits and disadvantages to the low-carbohydrate diet in conditions. 74
terms of the effect on the lipid profile compared to a low- The amount of activity to reduce one’s body weight is greater
fat diet. Greater decreases in triglycerides and increases in than the above minimum requirements. Evidence suggests that
HDL-cholesterol were noted in those individuals following the 450 min/week or at least 45 to 60 min/day is required for a
low-carbohydrate diet, but LDL-cholesterol decreased more in weight loss at the rate of 0.5 kg/week. 75,76 The amount of physi-
the low-fat diet groups. 62,63 Although greater short-term weight cal activity needed to maintain weight loss is greater than 60 min/
losses have been noted as a result of following a low-carbohydrate day or 2,500 kcal activity/week. 73,77 New recommendations
diet, long-term data are still lacking regarding the advantages of from the ACSM and AHA state that one should participate in at
this diet for weight loss maintenance, with adherence to the di- least 60 to 90 minutes of moderate activity in order to prevent
etary plan playing a more important role in weight loss than does weight gain. 73 Long-term weight loss requires that individuals
the type of diet. 64 A recent report of a 12-month trial found a expend 2,500 kcal/week, but this level of activity is very diffi-
low-carbohydrate diet to be superior for weight loss at 12 months, cult for both men and women to maintain once the treatment
although the mean weight loss was a moderate 4.7 kg. 65 period ends. 77
Another dietary plan for weight loss takes into consideration Various approaches are available for individuals beginning or
the glycemic index (GI) of food. The GI rates carbohydrate-rich expanding their exercise program. Adherence to exercise can be
food based upon whether the carbohydrate breaks down and is ab- influenced by several factors, including the environment (e.g., su-
sorbed slowly (low GI) or quickly (high GI) during digestion, and pervised or group exercise classes vs. exercising at home) and the
the effect on blood glucose levels. 66 How rapidly glucose enters economic resources or neighborhood. A recent report from the
the blood and the resultant insulin response may cause consider- NHANES data revealed that lower socioeconomic status has
able fluctuations in blood glucose, resulting in an individual’s the strongest effect on reported physical activity. 78 A study
hunger returning more quickly. 67 Findings regarding weight loss from the Netherlands found that the neighborhoods of lower so-
and a low-GI diet have been equivocal. Some suggest that fol- cioeconomic status individuals were often not conducive to exer-
lowing a low-GI dietary plan has no significant weight loss cise because of high traffic, poor lighting, and high crime rates. 79
70
benefit in either the short 68,69 or long term. A review of six ran- However, under the right conditions, having a patient follow an
domized controlled trials found greater reductions in body mass independent exercise program at home may result in improved
and total fat mass in those who received the low-GI diet com- adherence and weight loss. 58 Another strategy that may improve
pared with other diets, but the longest study was 6 months in exercise adherence as well as weight loss maintenance, includes
length with a 6-month follow up assessment. 71 A low-glycemic having the patient use several short bouts (10 minutes) of exercise
load diet has been noted to have a favorable effect on HDL and instead of the conventional long bout (20 to 40 minutes). 73
triglycerides but not on LDL. 72 Additional information from Bish et al. 11 studied the behaviors of Americans trying to lose
longer studies is needed before conclusions can be drawn about weight. They found that about 66% of both men and women use
this dietary plan. physical activity to assist with their weight loss. The proportion of
those utilizing physical activity for weight loss increased among
Exercise and Physical Activity individuals with more education and decreased with increased
Jakicic and Otto 58 describe the key to managing body weight in age. Among women trying to lose weight, non-Hispanic Whites
terms of energy balance; thus, theoretically, as long as energy in- reported using physical activity more often than Hispanic and
take equals energy expenditure, weight should be maintained. non-Hispanic Blacks. 11 Individuals who sought out regular care
This is the premise for avoiding initial weight gain or preventing with their primary care providers were also more likely to use
regain once weight loss occurs. They further state that in order to physical activity to assist with their weight loss.
lose weight, one must create an energy imbalance that elicits an Daily activity is another way of improving weight loss efforts.
energy deficit. 58 Exercise can provide that increase in energy ex- Incorporating activities that result in increased energy expenditure
penditure resulting in a deficit. (e.g., using the stairs and walking) can help to increase overall
The amount of physical activity necessary for weight reduction caloric expenditure. Another approach is to encourage patients to
is different from the amount of physical activity required for decrease the amount of sedentary activities (i.e., watching TV or
maintenance of one’s health. Current recommendations from the computer use) and replace them with activities such as gardening
American College of Sports Medicine (ACSM) and the American or recreational sports. Lifestyle activity can result in positive ben-
Heart Association (AHA) to improve health advise individuals be- efits on physical fitness and cardiovascular risk reduction. 58
tween the ages of 18 and 65 years to participate in moderate in- Depending on the patient’s age, risk factor profile, and con-
tensity aerobic physical activity (walking at 3.5 to 4.0 mph) for comitant conditions and symptoms, exercise testing to assess car-
a minimum of 30 minutes 5 days/week or vigorous intensity aer- diopulmonary function and presence of disease may be indicated.
obic activity (jogging or biking at 10 mph) for at least 20 minutes This needs to be determined before initiating an exercise program.
3 days/week in order to maintain one’s health. 73 A combination Patients also require instruction on injury prevention, how to ini-
of both moderate and vigorous intensity activity is encouraged, al- tiate and maintain an exercise program, proper attire, and weather
though not necessary. The updated recommendations also suggest conditions. The kind of activity or exercise and the amount of
that individuals will benefit from activities that increase muscle time spent engaged in it are recorded in the patient’s diaries. Lists