Dietary therapy in diabetes mellitus. Is there a single best diet?

The ideal diet for diabetic patients remains to be determined. Recommendations generally call for low-fat high-carbohydrate diets. The primary purpose of this recommendation is to reduce the risk for coronary heart disease, a major killer of diabetic patients. Some investigators also suggest that high-carbohydrate diets also improve glucose tolerance, even in patients with non-insulin-dependent diabetes mellitus (NIDDM). Another potential advantage of a low-fat diet (high percentage of carbohydrate) is that it may promote weight reduction. High-fat diets are thought by many investigators to stimulate weight gain. Thus, in obese NIDDM patients a trial of a low-fat weight-reduction diet may be worthwhile. However, if after an adequate trial of this diet, weight reduction is not achieved, this suggests that the patient is consuming large quantities of carbohydrates. The continued feeding of a high-carbohydrate diet to a persistently obese patient with NIDDM may have several untoward effects. For example, it can heighten hyperglycemia, raise plasma triglycerides, and lower high-density lipoproteins. In such dietary failures, it may be better to replace carbohydrate with fat to avoid these responses. Ideally, the fat should not raise the serum cholesterol level, and hence it should be unsaturated. Monounsaturated fatty acids seem preferable to polyunsaturated fatty acids, because polyunsaturates may increase the risk for cancer or promote the oxidation of low-density lipoprotein, another potentially atherogenic change. Many NIDDM patients, particularly obese patients in the earlier stages of diabetes, tolerate weight-maintenance high-carbohydrate diets without deterioration of glucose tolerance.(ABSTRACT TRUNCATED AT 250 WORDS)     

DIET AND TISSUE GROWTH : I. THE REGENERATION OF LIVER TISSUE ON VARIOUS ADEQUATE DIETS.

1. The toxicity of chloroform varies according to the diets used in these experiments in the following order of decreasing susceptibility of the animals: high fat > standard > high carbohydrate > high protein diets. 2. On the high fat and high carbohydrate diets there may be a more or less marked proliferation of the endothelium and the connective tissue stroma in the necrotic area producing in some instances scars resembling the picture of an early cirrhosis. 3. On the diets studied, standard, high carbohydrate, high protein, and high fat, the most active and rapid repair is observed on the standard balanced diet. On the high fat diet the reparative process is definitely delayed in comparison with the others. There are only slight differences between the high carbohydrate and high protein diets which suggest but do not conclusively show a more rapid repair with the latter diet.     

Dietary fiber in management of diabetes

Current evidence suggests that high-fiber diets, especially of the soluble variety, and soluble fiber supplements may offer some improvement in carbohydrate metabolism, lower total cholesterol and low-density lipoprotein (LDL) cholesterol, and have other beneficial effects in patients with non-insulin-dependent diabetes mellitus (NIDDM). Diets enriched with wheat bran and guar gum induce 10-20% reductions in serum cholesterol and LDL in both normo- and hypercholesterolemic subjects and have the ability to blunt the hypertriglyceridemic effects of diets high in carbohydrate and low in fiber. In insulin-dependent diabetes mellitus (IDDM) the situation is less clear, but a decrement of the circadian glucose profile has been shown. Americans, in general, consume too little fiber. With the need to restrict fat and reduce protein, an increase in carbohydrates is mandatory. A practical goal would be to establish the present level of fiber intake (15-30 g/day) and to gradually increase it. An intake of up to 40 g of fiber per day or 25 g/1000 kcal of food intake appears beneficial; in many individuals on weight-reducing diets higher levels may be unacceptable because of gastrointestinal side effects. The level of maximum benefit has not been determined. Fiber supplementation appears beneficial only if given with a diet comprising approximately half of the calories as carbohydrate. Foods should be selected with moderate to high amounts of dietary fiber from a wide variety of choices to include both soluble and insoluble types of fiber. Insufficient data are available on the long-term safety of high-fiber supplements. People at risk for deficiencies, such as postmenopausal women, the elderly, or growing children, may require supplements of calcium and trace minerals. People with upper gastrointestinal dysfunction are at risk of bezoar formation and cautioned against a diet high in fiber of the leafy vegetable type. Careful attention must be paid to insulin dose because hypoglycemia can result if there is a radical change in fiber intake and insulin dose is not reduced appropriately. Care must be exercised in the use of "novel" fibers, including the wood celluloses, because little is known of their safety and efficacy.     

Dietary fiber--an overview.

Diabetes diets should aim at ensuring an ideal body weight with normoglycemia and normolipidemia. The consensus recommendations of various diabetes associations suggest that these goals are most likely to be achieved by diets high in complex carbohydrates and fiber and low in fat. A typical diabetes diet containing 55-60% energy as carbohydrate (at least 66% complex), less than 30% energy as fat, 0.8 g.kg-1 desirable body wt.day-1 protein, and approximately 40 g fiber/day, improves glycemic control, reduces levels of serum atherogenic lipids, decreases blood pressure in those with hypertension, and reduces body weight in the obese. This diet also reduces insulin requirements in the insulin-treated patient and can promote discontinuation of insulin therapy in those with non-insulin-dependent diabetes mellitus. This article presents our experience with high-fiber high-carbohydrate diets and reviews knowledge on the likely mechanisms of action of fiber, its long-term effectiveness, and the concerns about its long-term safety. We suggest that reports on the risk of hypertriglyceridemia from on the risk of hypertriglyceridemia from high-carbohydrate diets are inconsistent and invalidated if those diets are also high in fiber content. Similarly, we urge some caution in prescribing high-monounsaturated fat diets as an alternative to high-carbohydrate diets, at least until the long-term implications of the former are clearer. We believe that there is no compelling reason to change the current diabetes diets, which should continue to be high in carbohydrate and fiber content.     

Role and management of exercise in diabetes mellitus

As more is understood about the physiology of exercise, in both normal and diabetic subjects, its role in the treatment of diabetes is becoming better defined. Whereas people with diabetes may derive many benefits from regular physical exercise, there are also several hazards that make exercise difficult to manage. In type I (insulin-dependent) diabetes, there are risks of hypoglycemia during or after exercise or of worsening metabolic control if insulin deficiency is present. Type II (non-insulin-dependent) diabetic patients treated with sulfonylureas are also at some increased risk of developing hypoglycemia during or after exercise, although this poses less of a problem than with insulin treatment. In individuals treated by diet alone, regulation of blood glucose during exercise is usually not a significant problem and exercise can be used as an adjunct to diet to achieve weight loss and improved insulin sensitivity. When obese type II diabetic patients are treated with very low calorie diets, adequate amounts of carbohydrate must be provided to ensure maintenance of normal muscle glycogen content, particularly if individuals wish to participate in high-intensity exercise that places a heavy workload on specific muscle groups. On the other hand, moderate-intensity exercise such as vigorous walking can be tolerated by individuals on very low calorie, carbohydrate-restricted diets after an appropriate period of adaptation. A number of strategies can be employed to avoid hypoglycemia in type I diabetic patients, and both type I and II diabetic patients should be examined carefully for long-term complications of their disease, which may be made worse by exercise. These considerations have led many diabetologists to consider exercise beneficial in the management of diabetes for some individuals but not recommended for everyone as a necessary part of diabetes treatment as in the past. The goals should be to teach patients to incorporate exercise into their daily lives if they wish and to develop strategies to avoid the complications of exercise. The rationale for the use of exercise as part of the treatment program in type II diabetes is much more clear than for type I diabetes; regular exercise may be prescribed as an adjunct to caloric restriction for weight reduction and as a means to improve insulin sensitivity in the obese insulin-resistant individual.     

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)     

High-fat diets: healthy or unhealthy?

In the current dietary recommendations for the treatment and prevention of Type 2 diabetes and its related complications, there is flexibility in the proportion of energy derived from monounsaturated fat and carbohydrate as a replacement for saturated fat. Over the last few years, several population studies have shown that subjects eating a lot of refined grains and processed foods have a much larger increase in waist circumference than those following a diet higher in monounsaturated fat, protein and carbohydrates rich in fibre and whole grain. In the present issue of Clinical Science, Sinitskaya and co-workers have demonstrated that, in normal-weight rodents categorized into groups of high-fat and medium-carbohydrate [53%/30% of energy as fat/carbohydrate; 19.66 kJ/g (4.7 kcal/g)], high-fat and low-carbohydrate [67%/9% of energy as fat/carbohydrate; 21.76 kJ/g (5.2 kcal/g)] and high-fat and carbohydrate-free [75%/0% of energy as fat/carbohydrate; 24.69 kJ/g (5.9 kcal/g)] diets, the high-fat diets containing carbohydrates were both obesogenic and diabetogenic, whereas the very-high-fat and carbohydrate-free diet was not obesogenic but led to insulin resistance and higher risk of cardiovascular disease. This finding may indicate that high-fat diets could easily give rise to an unhealthy diet when combined with carbohydrates, highlighting the significance of macronutrient composition, rather than caloric content, in high-fat diets.     

Exercise and diabetes mellitus

As more is understood about the physiology of exercise, both in normal and in diabetic subjects, its role in the treatment of diabetes is becoming better defined. Although persons with diabetes may derive many benefits from regular physical exercise, there also are a number of hazards that make exercise difficult to manage. In insulin-treated diabetics, there are risks of hypoglycemia during or after exercise or of worsening metabolic control if insulin deficiency is present. Type II diabetics being treated with sulfonylureas also are at some increased risk of developing hypoglycemia during or following exercise, although this is less of a problem than occurs with insulin treatment. In individuals treated by diet alone, regulation of blood glucose during exercise usually results in a decrease in glucose concentration toward normal but not to hypoglycemic levels and exercise can be used safely as an adjunct to diet to achieve weight loss and improved insulin sensitivity. When obese patients with type II diabetes are treated with very low calorie diets, adequate amounts of carbohydrate must be provided to ensure maintenance of normal muscle glycogen content, particularly if individuals wish to participate in high intensity exercise that places a heavy workload on specific muscle groups. On the other hand, moderate intensity exercise such as vigorous walking can be tolerated by individuals on very low calorie, carbohydrate-restricted diets after an appropriate period of adaptation. A number of strategies can be employed to avoid hypoglycemia in patients with insulin-treated diabetes and both type I and type II diabetic subjects should be examined carefully for long term complications of their disease, which may be worsened by exercise. These considerations have led many diabetologists to consider exercise to be beneficial in the management of diabetes for some individuals but not to be recommended for everyone as a "necessary" part of diabetic treatment as was thought in the past. Instead, the goals should be to teach patients to incorporate exercise into their daily lives if they wish and to develop strategies to avoid the complications of exercise. The rationale for the use of exercise as part of the treatment program in type II diabetes is much clearer and regular exercise may be prescribed as an adjunct to caloric restriction for weight reduction and as a means of improving insulin sensitivity in the obese, insulin-resistant individual.     

Persistence of hypertriglyceridemic effect of low-fat high-carbohydrate diets in NIDDM patients

Although low-fat high-carbohydrate diets are recommended for patients with non-insulin-dependent diabetes mellitus (NIDDM) in an effort to reduce the risk of coronary artery disease (CAD), the results of short-term studies have shown that these diets can lead to changes in carbohydrate and lipid metabolism associated with an increased risk of CAD. This study has extended these earlier observations by determining the metabolic effects of such diets over a longer period in these patients. The comparison diets contained either 40 or 60% of the total calories as carbohydrates, with reciprocal changes in fat content from 40 to 20% consumed in random order for 6 wk in a crossover experimental design. The ratio of polyunsaturated to saturated fat and the total cholesterol intake were held constant in the two diets. Plasma glucose and insulin concentrations were significantly (P less than .001) elevated throughout the day when patients consumed the 60% carbohydrate diet, and 24-h urinary glucose excretion more than doubled (0.8 vs. 1.8 mol/24 h). Fasting plasma total and very-low-density lipoprotein (VLDL) triglyceride (TG) concentrations increased by 30% (P less than .001) after 1 wk on the 60% carbohydrate diet, and the magnitude of carbohydrate-induced hypertriglyceridemia persisted unchanged throughout the 6-wk study period. Total plasma cholesterol concentrations were similar after both diets. However, VLDL cholesterol (VLDL-chol) was significantly increased, whereas both low-density lipoprotein (LDL-) and high-density lipoprotein (HDL-) chol concentrations were significantly decreased after consumption of the 60% carbohydrate diet. Consequently, neither total-chol-to-HDL-chol nor LDL-chol-to-HDL-chol ratios changed.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of dietary fiber and carbohydrate on glucose and lipoprotein metabolism in diabetic patients.

Dietary recommendations for the treatment of diabetic patients issued by national and international diabetes associations consistently emphasize the need to increase carbohydrate consumption. However, these recommendations have been questioned on the basis of growing evidence that, in both insulin-dependent and non-insulin-dependent diabetic patients, a high-carbohydrate diet does not offer any advantage in terms of blood glucose and plasma lipid concentrations compared with a high-fat (mainly unsaturated) diet. It has been shown repeatedly that a high-carbohydrate diet increases plasma insulin and triglyceride levels and can deteriorate blood glucose control in the postprandial period. However, much of the controversy between advocates and detractors of dietary carbohydrate can be settled by taking into account dietary fiber. Several studies have shown that the adverse metabolic effects of high-carbohydrate diets are neutralized when fiber and carbohydrate are increased simultaneously in the diet for diabetic patients. In particular, these studies demonstrated that a high-carbohydrate/high-fiber diet significantly improves blood glucose control and reduces plasma cholesterol levels in diabetic patients compared with a low-carbohydrate/low-fiber diet. In addition, a high-carbohydrate/high-fiber diet does not increase plasma insulin and triglyceride concentrations, despite the higher consumption of carbohydrates. Unfortunately, dietary fiber represents a heterogenous category, and there is still much to understand as to which foods should be preferred to maximize the metabolic effects of fiber. There are indications that only water-soluble fiber is active on plasma glucose and lipoprotein metabolism in humans. Therefore, in practice, the consumption of legumes, vegetables, and fruits--rich in water-soluble fiber--should be particularly encouraged. The mechanisms by which dietary fiber exerts its hypoglycemic and hypolipidemic activities are unknown. However, the ability of dietary fiber to retard food digestion and nutrient absorption certainly has an important influence on lipid and carbohydrate metabolism. The beneficial effects of high-fiber foods are also exerted by some foods not particularly rich in fiber. The fiber content and physical form of the food can influence the accessibility of nutrients by digestive enzymes, thus delaying digestion and absorption. The identification of these foods with a low-glycemic response would help enlarge the list of foods particularly suitable for diabetic patients. In conclusion, a diet low in cholesterol and saturated fat should be recommended to all diabetic patients to prevent cardiovascular disease. A balanced increase in consumption of fiber-rich foods and unsaturated fat is the most rational way to replace foods rich in saturated fat and cholesterol in the diabetic diet.     

Effect of digestible carbohydrates on glucose control in insulin-dependent diabetic patients

Recent studies have demonstrated that high-carbohydrate-high-fiber diets may improve the metabolic control in diabetes. To evaluate the influence of dietary carbohydrates separate from dietary fiber on blood glucose control, six insulin-dependent diabetic patients (IDD) were assigned in random order to two weight-maintaining diets for consecutive periods of 10 days. The diets differed in carbohydrate (41% in diet A and 60% in diet B) and fat content (41% and 20%, respectively) but were identical in calories, proteins, simple sugars, and fiber. After each dietary period blood glucose was continuously monitored for 24 h (Biostator GCIIS, Life Science Instruments, Miles Laboratories, Elkhart, Indiana). The M value was 48 +/- 20 after diet A and 96 +/- 27 after diet B (t = 3.83, P less than 0.025); the mean daily blood glucose was 152 +/- 5 mg/dl after diet A and 206 +/- 11 mg/dl after diet B (t = 7.50, P less than 0.001). Similarly, the blood glucose level for the 3-h period after each of the three main meals was lower after diet A than after diet B (analysis of variance: F = 5.2, P less than 0.05). No significant difference in fasting serum cholesterol, triglycerides, or serum lipoprotein composition was observed between the two diets. In order to separate the influence of dietary carbohydrate and fat on postprandial blood glucose concentration, an additional test meal experiment was performed in eight insulin-dependent diabetic patients. In random order on consecutive days they were given two standard meals that were identical in carbohydrate and protein content and differed only in the amount of olive oil added to the meals (12 g versus 36 g).(ABSTRACT TRUNCATED AT 250 WORDS)     

Vegetarian diet planning for adolescents with diabetes

Adolescents with insulin dependent diabetes mellitus (IDDM) who choose to be vegetarian have complex nutritional needs because of their continued physical growth and development, their participation in strenuous activities, and their need to consume sufficient carbohydrates to match their insulin doses. Since diet control is a cornerstone of diabetes management, the adolescent who chooses a vegetarian diet may cause their parents needless anxiety. Nurses working with these adolescents can provide support and guidance and liaison with the endocrinologist, nutritionist or dietitian, and diabetic educator. Although adolescent diabetic vegetarians have not been studied extensively as a population, facts about nutrition and diabetes can be used to assist in meal planning. A complete growth and nutritional assessment must be done to search for any problem areas. If protein dense flesh food is eliminated and a largely carbohydrate diet is consumed, there are additional areas of concern in regulating insulin needs. Blood glucose should be monitored very carefully during diet changes. Vegetarian girls with diabetes also should be carefully monitored for the adequacy of their diet because they may be at risk of developing an eating disorder.     

Metabolic effects of very low calorie weight reduction diets.

A randomized comparison trial of two very low calorie weight reduction diets was carried out for 5 or 8 wk in 17 healthy obese women. One diet provided 1.5 g protein/kg ideal body weight; the other provided 0.8 g protein/kg ideal body weight plus 0.7 g carbohydrate/kg ideal body weight. The diets were isocaloric (500 kcal). Amino acid metabolism was studied by means of tracer infusions of L-[1-13C]leucine and L-[15N]alanine. After 3 wk of adaptation to the diets, nitrogen balance was zero for the 1.5 g protein diet but -2 g N/d for the 0.8 g protein diet. Postabsorptive plasma leucine and alanine flux decreased from base line by an equal extent with both diets by approximately 20 and 40%, respectively. It was concluded that protein intakes at the level of the recommended dietary allowance (0.8 g/kg) are not compatible with nitrogen equilibrium when the energy intake is severely restricted, and that nitrogen balance is improved by increasing the protein intake above that level. Basal rates of whole body nitrogen turnover are relatively well maintained, compared with total fasting, at both protein intakes. However, turnover in the peripheral compartment, as evidenced by alanine flux, may be markedly diminished with either diet.     

Popular weight reduction diets

The percentage of people who are overweight and obese has increased tremendously over the last 30 years. It has become a worldwide epidemic. This is evident by the number of children are being diagnosed with a body mass index >85th percentile, and the number of children begin diagnosed with type 2 diabetes mellitus, a disease previously reserved for adults. The weight loss industry has also gained from this epidemic; it is a billion dollar industry. People pay large sums of money on diet pills, remedies, and books, with the hope of losing weight permanently. Despite these efforts, the number of individuals who are overweight or obese continues to increase. Obesity is a complex, multifactorial disorder. It would be impossible to address all aspects of diet, exercise, and weight loss in this review. Therefore, this article will review popular weight loss diets, with particular attention given to comparing low fat diets with low carbohydrate diets. In addition, the role that the environment plays on both diet and exercise and how they impact obesity will be addressed. Finally, the National Weight Control Registry will be discussed.     

Effect of dietary fat, carbohydrate, and protein on branched-chain amino acid catabolism during caloric restriction.

To assess the effect of each dietary caloric source on the catabolism of branched-chain amino acids, we investigated the rate of leucine oxidation before and after obese volunteers consumed one of the following diets for one week: (a) starvation, (b) 300 or 500 cal of fat/d, (c) 300 or 500 cal of carbohydrate/d, (d) 300 or 500 cal of protein/d, (e) a mixture of carbohydrate (300 cal/d) and fat (200 cal/d), or (f) a mixture of carbohydrate (300 cal/d) and protein (200 cal/d). Starvation significantly increased the rate of leucine oxidation (1.4 +/- 0.11 vs. 1.8 +/- 0.16 mmol/h, P less than 0.01). The same occurred with the fat and protein diets. In sharp contrast, the 500-cal carbohydrate diet significantly decreased the rate of leucine oxidation (1.3 +/- 0.13 vs. 0.6 +/- 0.09 mmol/h, P less than 0.01). The same occurred when a portion of the carbohydrate diet was isocalorically replaced with either fat or protein. The cumulative nitrogen excretion during the fat diet and starvation was not significantly different. As compared with the fat diets, the carbohydrate diets on the average reduced the urinary nitrogen excretion by 12 g/wk. Nitrogen balance was positive during the consumption of the 500-cal protein diet, but negative during the consumption of carbohydrate-protein diet. The fat diets, like the protein diets and starvation, greatly increased plasma leucine (119 +/- 13 vs. 222 +/- 15 microM, P less than 0.01) and beta-hydroxybutyrate (0.12 +/- 0.02 vs. 4.08 +/- 0.43 mM, P less than 0.01) concentrations, and significantly decreased plasma glucose (96 +/- 4 vs. 66 +/- 3 mg/dl, P less than 0.01) and insulin (18 +/- 4 vs. 9 +/- 1 microU/ml, P less than 0.05) concentrations. These changes did not occur, or were greatly attenuated, when subjects consumed carbohydrate alone or in combination with fat or protein. We conclude that during brief caloric restriction, dietary lipid and protein, unlike carbohydrate, do not diminish the catabolism of branched-chain amino acids and the decrease in branched-chain amino acid oxidation is associated with protein sparing.     

Dietary carbohydrate, a Big Mac, and insulin requirements in type I diabetes

Using the artificial beta-cell (Biostator), we determined the insulin requirements in five nonobese type I (insulin-dependent) diabetic subjects who received isocaloric 40 and 60% mixed-carbohydrate diets in a crossover randomized fashion for 4 days, each day consisting of four equal meals. This was followed on day 5 by a "Big Mac Attack" lunch consisting of a Big Mac, french fries, and milk shake. Insulin requirements to maintain normoglycemia were calculated for each 24-h period and for the 2 h after each meal. The mean 24-h insulin requirements to maintain normoglycemia was greater for the 60% carbohydrate diet than the 40% diet. Although the four meals were of equal size, in all patients the insulin required to cover breakfast greater than lunch greater than dinner greater than or equal to snack. Expressed as milliunits per kilocalorie, the amount of insulin to cover breakfast was greater for the 60% (P less than .05) than the 40% carbohydrate diet and greater for breakfast than the other meals (P less than .01). Insulin requirements for the Big Mac (43% carbohydrate) were 58% greater than for the 40% carbohydrate diet, even after correction for caloric differences. In summary, 1) increasing dietary carbohydrate from 40 to 60% results in an increased insulin requirement for meals only; 2) insulin requirements are greater in the morning than in the evening, even when meal size is constant; and 3) very large meals with high fat and carbohydrate content result in a major increase in insulin requirement. These data indicate that diet has an important impact on insulin requirements in diabetes.     

Beneficial effect of low-glycemic index diet in overweight NIDDM subjects.

OBJECTIVE--To determine whether low-glycemic index (GI) diets have clinical utility in overweight patients with non-insulin-dependent diabetes mellitus (NIDDM). RESEARCH DESIGN AND METHODS--Six patients with NIDDM were studied on both high- and low-GI diets of 6-wk duration with metabolic diets with a randomized crossover design. Both diets were of similar composition (57% carbohydrate, 23% fat, and 34 g/day dietary fiber), but the low-GI diet had a GI of 58 compared with 86 for the high-GI diet. RESULTS--Small and similar amounts of weight were lost on both diets: 2.5 kg on high-GI diet and 1.8 kg on low-GI diet. On the low-GI diet, the mean level of serum fructosamine, as an index of overall blood glucose control, was lower than on the high-GI diet by 8% (P less than 0.05), and total serum cholesterol was lower by 7% (P less than 0.01). CONCLUSIONS--In overweight patients with NIDDM, reducing diet GI improves overall blood glucose and lipid control.     

Lente carbohydrate: a newer approach to the dietary management of diabetes

The dietary fiber hypothesis has stimulated interest in the possibility that the glycemic response to carbohydrate foods may be reduced by modifying gastrointestinal events to produce sustained-release or "lente" carbohydrate. Associated with this interest, a new branch of pharmacology has been developed involving the use of purified fiber preparations and enzyme inhibitors. These measures, together with the selection of diets containing foods that naturally release their carbohydrate products of digestion slowly, may contribute a useful facet to diabetic management in the future.     

Benefits and limitations of very-low-calorie diet therapy in obese NIDDM

Weight reduction is one of the most effective therapies for obese non-insulin-dependent diabetes mellitus (NIDDM), but the success rate with conventional diets has been disappointing. The development of very-low-calorie diets (VLCDs) over the last two decades has provided an alternative approach to the treatment of uncomplicated obesity and is increasingly being used to treat obese NIDDM. This review focuses on the role of VLCDs in the treatment of obese NIDDM, the mechanisms underlying their efficacy, and the controversies surrounding their use. VLCDs provide 400-800 cal/day of high-quality protein and carbohydrate fortified with vitamins, minerals, and trace elements. Weight loss is initially very rapid, followed by steady reduction at a rate of 1-3 kg/wk. Metabolic benefits occur quickly with only modest weight reduction, suggesting that caloric restriction plays a more critical role. Multiple mechanisms account for improved glycemic control, including reduced hepatic glucose output, increased insulin action in the liver and peripheral tissues, and enhanced insulin secretion. VLCDs have the added benefit of rapid improvement in concomitant medical problems, particularly hypertension and hyperlipidemia, that could otherwise accelerate the development of some diabetic complications. Numerous controversies surround VLCD therapy, the most critical of which is its safety. However, recent studies indicate that VLCDs are safe for use by obese NIDDM patients in a medical setting closely supervised by an experienced physician. Contraindications to the diet, side effects, and recommended management are reviewed, as well as the role of adjunctive treatments, including behavioral modification and exercise. We present the perspective that, in most cases, the numerous metabolic benefits derived from VLCD therapy by the obese NIDDM patient outweigh its risks. Furthermore, recent data suggest that VLCD therapy may provide long-term benefits to the obese diabetic patient, despite weight regain.     

Insulin receptor binding increased by high carbohydrate low fat diet in non-insulin-dependent diabetics

Abstract. In comparison to a traditional low carbohydrate diet (LC), the effect of an isocaloric high carbohydrate, high fibre diet (HC) upon the insulin binding to mononuclear blood cells of seven non-insulin-dependent diabetics was examined. Each subject, in random order, took both diets for 6 weeks each. There was no significant difference in weight during either dietary period, but a significant ( P < 0.05) increase in the monocyte insulin binding activity on the HC diet (tracer specific binding: 4.2% HC; 3.5% LC). This was accompanied by a significantly ( P <0.02) lower fasting plasma glucose concentration (LC = 7.1 mmol/l; HC = 6.1) without a significant change in the fasting plasma insulin level. In contrast to the usual low carbohydrate diet, a high carbohydrate diet tends to correct the lowered insulin receptor status observed in maturity-onset diabetics.