Saturated fat and heart disease: The latest evidence

Greater improvements in diet quality among overweight participants following a group-based commercial weight loss programme than those receiving support to lose weight in primary care

BACKGROUND

Relatively little is known about dietary changes and their relationships with weight change during behavioural weight loss interventions. In a secondary analysis of data from a multicentre RCT, we investigated whether greater improvements in diet would be achieved by overweight adults following a 12 month group-based commercial weight loss programme (CP) than those receiving standard care (SC) in primary practice, and if these dietary changes were associated with greater weight loss.

METHODS

Adults with a BMI 27-35 kg/m2 and >1 risk factor for obesity-related disorders were recruited in study centres in Australia and the UK during 2007-2008. Dietary intake and body weight were measured at baseline, 6 and 12 months. Linear mixed effects models compared mean changes in dietary macronutrient intake, fibre density and energy density over time between groups, and their relationships with weight loss.

RESULTS

The CP group demonstrated greater mean weight loss than the SC group at 6 months (3.3 kg, 95% CI: 2.2, 4.4) and 12 months (3.3 kg, 95% CI: 2.1, 4.5). Diet quality improved in both intervention groups at 6 and 12 months. However, the CP group (n = 228) achieved significantly greater mean reductions in energy intake (mean difference; 95% CI: - 503 kJ/d; - 913, - 93), dietary energy density (- 0.48 MJ/g; - 0.81, - 0.16), total fat (- 6.9 g/d; - 11.9, - 1.8), saturated fat (- 3.3 g/d; - 5.4, - 1.1), and significantly greater mean increases in fibre density (0.30 g/MJ; 0.15, 0.44) at 6 months than the SC group (n = 239). Similar differences persisted at 12 months and the CP group showed greater mean increases in protein density (0.65 g/MJ). In both groups, weight loss was associated with increased fibre density (0.68 kg per g/MJ, 95% CI: 0.08, 1.27) and protein density (0.26 kg per g/MJ, 95% CI: 0.10, 0.41).

CONCLUSIONS

Following a group-based commercial program led to greater improvements in diet quality than standard care. Increases in dietary protein and fibre density were independently associated with weight loss in both behavioural weight loss interventions. Greater increases in protein and fibre density in the commercial program likely contributed to their greater weight loss.

TRIAL REGISTRATION

ISRCTN: ISRCTN85485463 Registered 03/08/2007 Retrospectively Registered.

Estimates of the direct and indirect cost savings associated with heart disease that could be avoided through dietary change in the United States

AIMS

Diets high in saturated fat are associated with elevated risk of heart disease. This study estimates the savings in direct (medical care) costs and indirect (job absenteeism) costs in the US from reductions in heart disease associated with substituting monounsaturated fats (MUFA) for saturated fats.

MATERIALS AND METHODS

A four-part model of the medical care cost savings from avoided heart disease was estimated using data on 247,700 adults from the 2000-2010 Medical Expenditure Panel Survey (MEPS). The savings from reduced job absenteeism due to avoided heart disease was estimated using a zero-inflated negative binomial model of the number of annual work loss days applied to data on 164,577 adults from the MEPS.

RESULTS

Estimated annual savings in medical care expenditures resulting from a switch from a diet high in saturated fat to a high-MUFA diet totaled ∼ $25.7 billion (95% CI = $6.0-$45.4 billion) in 2010, with private insurance plans saving $7.9 billion (95% CI = $1.8-$14.0 billion), Medicare saving $9.4 billion (95% CI = $2.1-$16.7 billion), Medicaid saving $1.4 billion (95% CI = $0.2-$2.5 billion), and patients saving $2.2 billion (95% CI = $0.5-$3.8 billion). The annual savings in terms of reduced job absenteeism ranges from a lower bound of $600 million (95% CI = $100 million to $1.0 billion) to an upper bound of $1.2 billion (95% CI = $0.2-$2.1 billion) for 2010.

LIMITATIONS

The data cover only the non-institutionalized population. Decreased costs due to any decreases in the severity of heart disease are not included. Cost savings do not include any reduction in informal care at home.

CONCLUSIONS

Diets high in saturated fat impose substantial medical care costs and job absenteeism costs, and substantial savings could be achieved by substituting MUFA for saturated fat.