Lifestyle Modification: Is It Achievable and Durable?

The epidemic of high blood pressure (BP) results in large part from prolonged exposure to adverse lifestyles (excessive salt intake, insufficient potassium intake, excessive alcohol intake, an otherwise unhealthy diet, being overweight, and a sedentary lifestyle). Hence, achieving and sustaining lifestyle modifications are critical components of public health efforts designed to lower BP and thereby prevent BP‐related cardiovascular‐kidney disease. Numerous controlled trials, often short‐term, have documented that lifestyle modifications are achievable and effective. While relapse is commonplace, long‐term trials, some lasting up to 4 years, have documented that individuals can sustain lifestyle changes and that these changes lower BP. Other types of studies, for example, the National Weight Control Registry, have also documented that individuals can sustain behavior change. This paper describes factors associated with successful maintenance of behavior change with a particular focus on weight loss.

ROLE OF LIFESTYLE MODIFICATIONS

Lifestyle modification, also termed nonpharmacologic therapy, has an important role in both nonhypertensive and hypertensive individuals. In nonhypertensive individuals, including those with prehypertension, lifestyle modifications have the potential to prevent hypertension and more broadly to reduce BP and thereby lower the risk of BP‐related clinical complications. Even an apparently small reduction in BP, if applied broadly to an entire population, could have an enormous beneficial impact in preventing cardiovascular disease. For example, it has been estimated that a population‐wide 3 mm Hg reduction in systolic BP could reduce stroke mortality by 8% and coronary heart disease mortality by 5%. In hypertensive individuals, lifestyle modifications can serve as initial treatment before the start of drug therapy and as an adjunct to drug therapy in persons already on medication. In hypertensive individuals with medication‐controlled BP, these therapies can facilitate drug step down and potentially drug withdrawal in individuals who sustain lifestyle changes.

Current lifestyle recommendations for the prevention and treatment of hypertension are displayed in Table I. Numerous short‐term trials have documented that individuals can make these lifestyle changes, which lower BP. A recent trial ¹ has documented that individuals can simultaneously make multiple lifestyle changes. A more vexing issue, the topic of this paper, is the extent to which individuals can sustain lifestyle changes over the long term. This issue has been addressed in several long‐term trials.

Table I.

Lifestyle Modifications That Lower Blood Pressure

<100 mmol (2.3 g) of sodium per day

>120 mmol (4.7 g) of potassium per day

An overall healthy diet (DASH diet)

Maintenance of an ideal body weight

At least 30 minutes on moderate aerobic activity most days of the week

Moderation of alcohol intake to ≤2 drinks per day in men and ≤1 drink per day in women

DASH=Dietary Approaches to Stop Hypertension

CLINICAL TRIALS WITH LONG‐TERM INTERVENTIONS

Phase 2 of the Trials of Hypertension Prevention (TOHP2)

TOHP2 was a 2×2 factorial trial ² that tested the effects of weight loss and/or a reduced salt intake as a means to prevent hypertension in 2383 middle‐aged adults (66% men, 82% non‐black), ages 30–54, with a diastolic BP of 83–89 mm Hg and a systolic BP <140 mm Hg. The interventions had a traditional format that started with an intensive phase followed by an extended maintenance phase with monthly group sessions. At 6 months, the height of intervention adherence, the incidence of hypertension was lowest in the combined group (2.7%), intermediate in the weight loss alone (4.2%) and sodium reduction alone (4.5%) groups, and highest in the control group (7.3%). At 18 months, the pattern persisted. By the end of the follow‐up (up to 4 years after randomization), the incidence of hypertension was 18%–22% less in each lifestyle group (p<0.05 compared with control) but not different from each other. Results of this trial indicate that lifestyle interventions can prevent hypertension over the long term.

Detailed analyses of those people assigned to the weight loss alone and control groups provide further insights into the impact of sustained weight loss on BP and incident hypertension. ³ , Figure 1 displays systolic BP reduction in the control group, as well as BP reduction in three subgroups of the weight loss alone intervention: 1) those who did not lose weight; 2) those who lost weight but regained it; and 3) those who successfully maintained weight loss of ≥4.5 kg. Among the 73 (13%) weight loss participants who lost ≥4.5 kg at 6 months without regaining it by 36 months, systolic BP reductions persisted; the incidence of hypertension was also reduced by 65% in comparison to the control group. In contrast, those participants assigned to the weight loss group who initially lost ≥4.5 kg but regained it and those who never lost weight had a systolic BP at 36 months that was no different from the control group.

Figure 1.

Mean systolic blood pressure (BP) in the Phase 2 of the Trials of Hypertension Prevention control group, as well as BP reduction in three subgroups of the weight loss intervention: 1) those who did not lose weight; 2) those who lost weight but regained it; and 3) those who successfully maintained weight loss of at least 4.5 kg. Adapted with permission from Ann Intern Med. 2001;134:7–11. ³

This trial also highlights the importance of a concurrent control group in the interpretation of weight loss interventions. On average, the control group continued to gain weight over 36 months of follow‐up. The active intervention group, which lost weight initially, regained weight to near baseline levels. Hence, in this trial, the weight loss intervention prevented long‐term weight gain that otherwise might have occurred.

Trials of Non‐Pharmacologic Interventions in the Elderly (TONE)

TONE ⁴ was a randomized trial that tested the effects of reduced sodium intake and weight loss, alone and combined, on BP control. Trial participants were 975 hypertensives (52% men, 77% non‐black), ages 60–80 years, with a baseline systolic/diastolic BP <145/85 mm Hg, on one medication. In a 2×2 factorial design, overweight participants were assigned to usual care, sodium reduction alone, weight loss alone, or combined weight loss/sodium reduction. Medication withdrawal was attempted 3 months after the start of interventions. The primary outcome variable was a composite endpoint defined primarily by the occurrence, after medication withdrawal, of an average BP >150/90 mm Hg or resumption of medication. Average follow‐up was 2.5 years. Compared with the control group, each of the active interventions led to improved BP control as defined by a greater fraction of individuals who did not require resumption of medication.

One of the most impressive features of TONE was that active intervention participants achieved and sustained lifestyle modification without evidence of relapse. Those people assigned to a sodium reduction intervention achieved and sustained an average reduction in sodium intake of ?40 mmol/d (Figure 2). Likewise, those assigned to a weight loss intervention achieved and sustained an average reduction in weight of ?10 lb (Figure 3). Possible reasons for successful maintenance are: 1) the study population, which consisted of older persons with established hypertension, that is, individuals who might be more able and committed to making lifestyle changes than younger individuals without hypertension and 2) the use of individual counseling sessions during its maintenance phase.

Figure 2.

Mean change in urinary sodium excretion (mmol/24 hr) in Trials of Non‐Pharmacologic Interventions in the Elderly participants assigned to a reduced sodium group vs. those not assigned to a reduced sodium group. Adapted with permission from JAMA. 1998;279:839–846. ⁴

Figure 3.

Mean change in body weight (kg) in Trials of Non‐Pharmacologic Interventions in the Elderly participants assigned to a weight loss group vs. those not assigned to a weight loss group.
Adapted with permission from JAMA. 1998;279:839–846. ⁴

THE NATIONAL WEIGHT CONTROL REGISTRY

The National Weight Control Registry, ⁵ founded in 1994, is an ongoing observational study to assess factors associated with sustained weight loss. To be eligible for this registry, individuals must have maintained at least a 30‐lb weight loss for at least 1 year. Of the initial >3000 participants (80% women, 97% white, mean age of 45 years), the average reported weight loss was 66 lb and the average duration of weight loss was 5.5 years. On average, their body mass index was 10 body mass index units lower than their pre‐weight loss level. Almost 90% reported previous unsuccessful attempts at weight loss.

In this registry, 89% of individuals reported modifying both diet and exercise to achieve their initial weight loss. Of those who modified diet intake, the most common methods were restricting certain types of foods (88%), limiting quantities (44%), and counting calories (44%). Overall, 40% of women and 63% of men reported losing weight on their own, while the remainder used a commercial weight loss program to achieve their weight loss.

While the strategies to lose weight differed among participants, strategies to maintain weight loss tended to be similar. Three common strategies, listed in Table II, were: 1) eating a low‐fat, low‐calorie diet; 2) self‐monitoring frequently; and 3) engaging in regular physical activity. Average macronutrient composition of the participants is displayed in Figure 4. It is important to emphasize that extremely few participants (<1%) consumed a very low carbohydrate diet (<24% kcal from carbohydrates, or <90 g of carbohydrates per 1500 kcal). Despite the popularity of low‐carbohydrate diets, there is no evidence that such diets are effective in the long term. Individuals monitored their weight frequently (44% at least once daily, and another 31% at least weekly). Regular physical activity was almost universal; just 9% of individuals used calorie reduction without regular physical activity. The average amount of physical activity was the equivalent of approximately 1 hour of brisk walking per day. Other studies ⁶ have documented that a direct association between the amount of physical activity and the extent of weight loss exists (Figure 5).

Table II.

Behaviors Associated With Successful Weight Maintenance: Results From the National Weight Control Registry

Self‐monitoring

Diet: record food intake daily

Weight: check body weight ≥1 time/wk

Low‐calorie, low‐fat diet

Total energy intake: 1300–1400 kcal/d

Energy intake from fat: 20%–25%

Regular physical activity

2500–3000 kcal/wk (e.g., walk of 4 mi/d)

Figure 4.

Average macronutrient composition of diet consumed by individuals who successfully maintained weight loss: results from the National Weight Control Registry

Figure 5.

Average weight loss over 18 months stratified by amount of physical activity.
Adapted with permission from JAMA. 1999;282:1554–1560. ⁶

SUMMARY

Despite pessimism that lifestyle changes cannot be maintained, there is substantial evidence that many individuals can sustain them. Older‐aged persons are one subgroup of the population that has repeatedly been shown to achieve and sustain lifestyle modifications. Behavioral factors associated with maintenance of weight loss are a low‐calorie, low‐fat diet self‐monitoring and regular physical activity. Of course, these dimensions focus on individual behavior. The explosive, worldwide increase in the prevalence of the overweight and obese certainly reflects environmental factors that affect whole populations. Hence the most effective strategies will likely be environmental interventions that influence cultural factors, societal norms, and commercial interests.