The traditional Pima Indian diet. Composition and adaptation for use in a dietary intervention study.

OBJECTIVE: To examine changes in the Pima Indian diet composition that may have played a role in the dramatic rise in the incidence of NIDDM among Pima Indians over the last century. RESEARCH DESIGN AND METHODS: We investigated the composition of the foods comparable to those available to the Pima approximately 100 yr ago, with the aim of reproducing this traditional diet as faithfully as possible for a dietary intervention study. An approximation of the traditional diet was ascertained from the ethnohistoric literature and traditional recipes. RESULTS: We estimated that the traditional Pima diet, although seasonably variable, was approximately 70-80% carbohydrate, 8-12% fat, and 12-18% protein. A diet analogous to the traditional Pima diet is largely reproducible with the foods available today. Many native foods are available locally and many commercial products can be substituted when native foods are unavailable. CONCLUSIONS: The Pima Indian diet of the last century was much higher in carbohydrate and lower in fat compared with the modern-day Pima diet. Any changes that this diabetes-prone population can make toward their traditional diet may help to decrease their incidence of diabetes.

Effects of replacing saturated fat with complex carbohydrate in diets of subjects with NIDDM.

This study examined the safety of an isocaloric high-complex carbohydrate low-saturated fat diet (HICARB) in obese patients with non-insulin-dependent diabetes mellitus (NIDDM). Although hypocaloric diets should be recommended to these patients, many find compliance with this diet difficult; therefore, the safety of an isocaloric increase in dietary carbohydrate needs assessment. Lipoprotein cholesterol and triglyceride (TG, mg/dl) concentrations in isocaloric high-fat and HICARB diets were compared in 7 NIDDM subjects (fat 32 +/- 3%, fasting glucose 190 +/- 38 mg/dl) and 6 nondiabetic subjects (fat 33 +/- 5%). They ate a high-fat diet (43% carbohydrate; 42% fat, polyunsaturated to saturated 0.3; fiber 9 g/1000 kcal; cholesterol 550 mg/day) for 7-10 days. Control subjects (3 NIDDM, 3 nondiabetic) continued this diet for 5 wk. The 13 subjects changed to a HICARB diet (65% carbohydrate; 21% fat, polyunsaturated to saturated 1.2; fiber 18 g/1000 kcal; cholesterol 550 mg/day) for 5 wk. NIDDM subjects on the HICARB diet had decreased low-density lipoprotein cholesterol (LDL-chol) concentrations (107 vs. 82, P less than .001), but their high-density lipoprotein cholesterol (HDL-chol) concentrations, glucose, and body weight were unchanged. Changes in total plasma TG concentrations in NIDDM subjects were heterogeneous. Concentrations were either unchanged or had decreased in 5 and increased in 2 NIDDM subjects. Nondiabetic subjects on the HICARB diet had decreased LDL-chol (111 vs. 81, P less than .01) and unchanged HDL-chol and plasma TG concentrations).(ABSTRACT TRUNCATED AT 250 WORDS)

Deterioration in carbohydrate metabolism and lipoprotein changes induced by modern, high fat diet in Pima Indians and Caucasians.

The transition from a high carbohydrate to a high fat diet may explain in part the dramatic increase in the prevalence of noninsulin-dependent diabetes mellitus among Pima Indians over the last century. In this study, 12 Pimas and 12 caucasians, all nondiabetic, were admitted to a metabolic ward and, in random order, fed 2 14-day weight-maintaining diets: a traditional Pima diet (percentage of calories: carbohydrate, 70% fat, 15%; protein, 15%) and a high fat modern diet (carbohydrate, 30%; fat, 50%; protein, 20%). Carbohydrate metabolism was characterized using the modified iv glucose tolerance test (minimal model), the acute insulin responses to arginine during a 3-step glycemic clamp, and the oral glucose tolerance test. Compared with the traditional diet, the modern diet was associated with a decrease in oral glucose tolerance (P less than 0.01) and higher plasma cholesterol concentrations (P less than 0.02). The decline in glucose tolerance was associated with similar insulin-mediated, but 23% lower glucose-mediated (P less than 0.001), glucose disposal, a 17% lower acute insulin response to glucose (P less than 0.03), a 9% lower beta-cell sensitivity to glucose (P less than 0.02), and similar beta-cell capacities. Pimas and caucasians responded similarly, except for larger changes in plasma lipids among the Pimas. Since glucose-mediated glucose disposal, beta-cell function, and glucose tolerance deteriorated on the modern diet, it is likely that diet composition affects the prevalence of noninsulin-dependent diabetes mellitus in both Pimas and caucasians.

Insulin-sensitive tyrosine kinase activity changes in parallel with plasma insulin and glucose concentrations in humans.

Insulin receptor tyrosine kinase is an important step in insulin action. We examined the relationship between diet-induced changes in glucose metabolism and changes in skeletal muscle insulin-sensitive tyrosine kinase activity in 12 nondiabetic subjects. Subjects were fed a traditional, high carbohydrate Pima Indian diet and a modern, high fat western diet for 2 weeks in a randomized cross-over design. At the end of each dietary period, glucose tolerance was assessed, insulin sensitivity (SI) was estimated by Bergman's minimal model method, and insulin receptor concentration and tyrosine kinase activity were determined on lectin-purified extracts from quadriceps femoris muscle. Compared to the traditional diet, the modern diet was associated with a deterioration of glucose tolerance and an increase in glucose-induced plasma insulin levels. As expected, SI changes were associated with opposite changes in plasma insulin levels. However, the changes in maximal tyrosine kinase activity were negatively correlated with changes in SI (r = -0.69; P less than 0.01) and positively correlated with changes in plasma glucose (r = 0.70; P less than 0.01) and insulin response to glucose (r = 0.57; P less than 0.025). These results suggest that the site of diet-induced changes in insulin action is beyond the insulin-sensitive tyrosine kinase. The results further suggest that the kinase activity is modulated by prevailing plasma insulin levels.

Energy cost of physical activity on a metabolic ward in relationship to obesity.

The energy cost of physical activity on a metabolic ward was derived from the difference between the energy requirement to maintain body weight on a metabolic ward and sedentary 24-h energy expenditure measured in a respiratory chamber in 56 nondiabetic male subjects. The cost of physical activity was negatively correlated with body weight (r = -0.67, P less than 0.0001) and with percent body fat (r = -0.48, P less than 0.0005). In a subgroup of 15 subjects selected for strict weight stability (rate of daily weight change less than +/- 35 g/d), similar negative correlations were observed between energy cost of activity and body weight (r = -0.61, P less than 0.01) and percent body fat (r = -0.51, P = 0.05). The ratio of active to sedentary energy expenditure, an index of physical activity, was also negatively correlated with body weight and percent body fat (r = -0.74, P less than 0.002 and r = -0.61, P less than 0.02, respectively). These results suggest that heavier subjects on a metabolic ward are less active and expend less energy in physical activity than do lighter subjects.

Food intake measured by an automated food-selection system: relationship to energy expenditure.

Measuring food intake in a laboratory usually involves limited food choices. An automated food-selection system with two vending machines containing a large variety of foods was used to measure food intake in 10 male volunteers (31 +/- 6 y, 69.2 +/- 7.1 kg, 18 +/- 7% fat, mean +/- SD) on a metabolic ward. The effect of carbohydrate, fat, and protein intakes on 24-h energy expenditure (24EE) and substrate oxidations was measured in a respiratory chamber during day 4 of weight maintenance and day 7 of ad libitum intake. Ad libitum intake resulted in a 7-d overfeeding of 6468 +/- 3824 kJ/d above weight-maintenance requirements, leading to a 2.3 +/- 1.2-kg gain. The 10,975 +/- 3774 kJ excess energy intake on day 7 of ad libitum intake caused a 1205 +/- 920 kJ/d increase in 24EE (delta 24EE = 0.17 x delta intake - 695; r = 0.71, P less than 0.02). Of the excess carbohydrate intake, 74% was oxidized (r = 0.86, P less than 0.001), whereas excess fat intake was not. Carbohydrate and protein stores are regulated whereas excess fat intake is channeled to fat stores.

Effect of phenylpropanolamine on energy expenditure and weight loss in overweight women.

The effect of phenylpropanolamine (PPA), a noncatecholamine sympathomimetic weight-loss agent, on energy expenditure (EE) and substrate oxidation was measured in a respiratory chamber in 24 overweight women after 4 d of treatment (PPA or placebo) during weight maintenance and after 7 wk of treatment on a hypoenergetic diet (70% of measured baseline 24-h EE). Twelve women (37 +/- 2 y, 74 +/- 6 kg, 33 +/- 1% body fat) were randomly assigned to the PPA group [75 mg osmotic release oral system (OROS)-PPA/d] and 12 (mean +/- SEM: 38 +/- 2 y, 79 +/- 1 kg, 37 +/- 1% body fat) to the placebo group. Baseline measurements of 24-h EE (7849 +/- 226 vs 7834 +/- 142 kJ/d), basal metabolic rate (BMR) and 24-h respiratory quotient (RQ) were comparable between PPA and placebo groups. After 4 d of treatment, there was no significant effect of PPA on 24-h EE, BMR, and 24-h RQ compared with placebo. Over the 7-wk diet period, however, the PPA group (n = 8) had greater weight loss than the placebo group (n = 10): -5.0 +/- 0.5 vs -3.0 +/- 0.4 kg (P < 0.05). The changes in 24-h EE and 24-h RQ over the 7 wk were not different between the groups. We conclude that weight loss is enhanced by OROS-PPA, but this change was not explained by changes in 24-h EE or 24-h RQ. The small number of subjects may have hindered detection of subtle differences in energy metabolism.

Appendicitis complicating pregnancy.

Abdominal pain is a common symptom in pregnancy. Its etiology is diverse and diagnosis often poses a problem. Inflammatory disorders of extra-uterine origin such as appendicitis should always be considered as a possible cause. Three cases of appendicitis complicating pregnancy managed at the Queen Elizabeth Hospital, Barbados during the year 1993 are documented. Two presented in the antenatal period and the third postpartum. The clinical manifestations and the difficulties encountered in diagnosis are emphasised.

A prospective study of asymptomatic Chlamydia trachomatis in Barbadian women.

A prospective study to determine the prevalence of asymptomatic female genital tract Chlamydia trachomatis infection was performed on 167 women at the Queen Elizabeth Hospital, Barbados, West Indies and at a private clinic. The ELISA (Microtrak, chlamydia EIA, Syva, CA) method was used to detect Chlamydia trachomatis antigen. Nineteen (11.4% 95% CI 6.5-16.3) women were found positive. The efficacy of a single 1 gram dose of azithromycin given orally to 18 patients was tested after 4 weeks. One patient who was pregnant was given 500 mg erythromycin four times daily orally for 1 week. Only six patients (including the pregnant patient) reported for follow up. All six repeat swabs were negative for C. trachomatis antigen. The prevalence of 11.4% asymptomatic chlamydial infection in endocervical swabs in Barbadian women is in agreement with a previous study which reported a prevalence of 18.4% +/7.8%. Patient compliance was assured, using a single dose of azithromycin. It was found to be as effective as doxycyline and ciprofloxacin as reported by other workers.

Reduced rate of energy expenditure as a risk factor for body-weight gain.

The contribution of reduced energy expenditure to the development of obesity has been a point of controversy. We measured 24-hour energy expenditure (adjusted for body composition, age, and sex), in a respiratory chamber, in 95 southwestern American Indians. Energy expenditure correlated with the rate of change in body weight over a two-year follow-up period (r = -0.39, P less than 0.001). The estimated risk of gaining more than 7.5 kg in body weight was increased fourfold in persons with a low adjusted 24-hour energy expenditure (200 kcal per day below predicted values) as compared with persons with a high 24-hour energy expenditure (200 kcal per day above predicted values; P less than 0.01). In another 126 subjects, the adjusted metabolic rate at rest at the initial visit was also found to predict the gain in body weight over a four-year follow-up period. When the 15 subjects who gained more than 10 kg were compared with the remaining 111 subjects, the initial mean (+/- SD) adjusted metabolic rate at rest was lower in those who gained weight (1694 +/- 103 vs. 1764 +/- 109 kcal per day; P less than 0.02) and increased to 1813 +/- 134 kcal per day (P less than 0.01) after a mean weight gain of 15.7 +/- 5.7 kg. In a group of 94 siblings from 36 families, values for adjusted 24-hour energy expenditure aggregated in families (intraclass correlation = 0.48). We conclude that a low rate of energy expenditure may contribute to the aggregation of obesity in families.

Short-term energy balance: relationship with protein, carbohydrate, and fat balances.

Energy balance (energy intake-energy expenditure) is known to vary considerably on a day-to-day basis in free-living individuals. The extent to which stores of protein, carbohydrate, and fat are used to store short-term surpluses of energy and the extent to which these stores are used to make up temporary energy deficits are incompletely known. We have measured body energy balance as well as carbohydrate, fat, and protein balances in 27 Caucasian men and 27 Caucasian women over a 24-h period in a respiratory chamber. An estimated weight-maintenance diet was fed to each subject. Because of individual differences in family background, body composition, activity, and the failure of some subjects to eat all of their food, these estimates are not exact, and energy balance is rarely achieved. Energy balance was correlated with fat balance in men (r = 0.79, P less than 0.0001) and women (r = 0.72, P less than 0.0001), and the slope of this relationship was not distinguishable from unity in men (1.16 +/- 0.18) or women (0.80 +/- 0.15). There were no correlations between energy balance and either carbohydrate or protein balances. This study demonstrates that carbohydrate and protein stores are closely regulated by adjusting oxidation to intake. Thus fat, rather than carbohydrate or protein, is almost exclusively used or stored in response to day-to-day fluctuations in energy balance.