A crossover trial of high and low sucrose-carbohydrate diets in type II diabetics with hypertriglyceridemia

Important food sources of fructose-containing sugars and adiposity: A systematic review and meta-analysis of controlled feeding trials

BACKGROUND

Sugar-sweetened beverages (SSBs) providing excess energy increase adiposity. The effect of other food sources of sugars at different energy control levels is unclear.

OBJECTIVES

To determine the effect of food sources of fructose-containing sugars by energy control on adiposity.

METHODS

In this systematic review and meta-analysis, MEDLINE, Embase, and Cochrane Library were searched through April 2022 for controlled trials ≥2 wk. We prespecified 4 trial designs by energy control: substitution (energy-matched replacement of sugars), addition (energy from sugars added), subtraction (energy from sugars subtracted), and ad libitum (energy from sugars freely replaced). Independent authors extracted data. The primary outcome was body weight. Secondary outcomes included other adiposity measures. Grading of Recommendations Assessment, Development, and Evaluation (GRADE) was used to assess the certainty of evidence.

RESULTS

We included 169 trials (255 trial comparisons, n = 10,357) assessing 14 food sources at 4 energy control levels over a median 12 wk. Total fructose-containing sugars increased body weight (MD: 0.28 kg; 95% CI: 0.06, 0.50 kg; P_MD = 0.011) in addition trials and decreased body weight (MD: -0.96 kg; 95% CI: -1.78, -0.14 kg; P_MD = 0.022) in subtraction trials with no effect in substitution or ad libitum trials. There was interaction/influence by food sources on body weight: substitution trials [fruits decreased; added nutritive sweeteners and mixed sources (with SSBs) increased]; addition trials [dried fruits, honey, fruits (≤10%E), and 100% fruit juice (≤10%E) decreased; SSBs, fruit drink, and mixed sources (with SSBs) increased]; subtraction trials [removal of mixed sources (with SSBs) decreased]; and ad libitum trials [mixed sources (with/without SSBs) increased]. GRADE scores were generally moderate. Results were similar across secondary outcomes.

CONCLUSIONS

Energy control and food sources mediate the effect of fructose-containing sugars on adiposity. The evidence provides a good indication that excess energy from sugars (particularly SSBs at high doses ≥20%E or 100 g/d) increase adiposity, whereas their removal decrease adiposity. Most other food sources had no effect, with some showing decreases (particularly fruits at lower doses ≤10%E or 50 g/d). This trial was registered at clinicaltrials.gov as NCT02558920 (https://clinicaltrials.gov/ct2/show/NCT02558920).

Food sources of fructose-containing sugars and glycaemic control: systematic review and meta-analysis of controlled intervention studies

OBJECTIVE

To assess the effect of different food sources of fructose-containing sugars on glycaemic control at different levels of energy control.

DESIGN

Systematic review and meta-analysis of controlled intervention studies.

DATA SOURCES

Medine, Embase, and the Cochrane Library up to 25 April 2018.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Controlled intervention studies of at least seven days' duration and assessing the effect of different food sources of fructose-containing sugars on glycaemic control in people with and without diabetes were included. Four study designs were prespecified on the basis of energy control: substitution studies (sugars in energy matched comparisons with other macronutrients), addition studies (excess energy from sugars added to diets), subtraction studies (energy from sugars subtracted from diets), and ad libitum studies (sugars freely replaced by other macronutrients without control for energy). Outcomes were glycated haemoglobin (HbA1c), fasting blood glucose, and fasting blood glucose insulin.

DATA EXTRACTION AND SYNTHESIS

Four independent reviewers extracted relevant data and assessed risk of bias. Data were pooled by random effects models and overall certainty of the evidence assessed by the GRADE approach (grading of recommendations assessment, development, and evaluation).

RESULTS

155 study comparisons (n=5086) were included. Total fructose-containing sugars had no harmful effect on any outcome in substitution or subtraction studies, with a decrease seen in HbA1c in substitution studies (mean difference -0.22% (95% confidence interval to -0.35% to -0.08%), -25.9 mmol/mol (-27.3 to -24.4)), but a harmful effect was seen on fasting insulin in addition studies (4.68 pmol/L (1.40 to 7.96)) and ad libitum studies (7.24 pmol/L (0.47 to 14.00)). There was interaction by food source, with specific food sources showing beneficial effects (fruit and fruit juice) or harmful effects (sweetened milk and mixed sources) in substitution studies and harmful effects (sugars-sweetened beverages and fruit juice) in addition studies on at least one outcome. Most of the evidence was low quality.

CONCLUSIONS

Energy control and food source appear to mediate the effect of fructose-containing sugars on glycaemic control. Although most food sources of these sugars (especially fruit) do not have a harmful effect in energy matched substitutions with other macronutrients, several food sources of fructose-containing sugars (especially sugars-sweetened beverages) adding excess energy to diets have harmful effects. However, certainty in these estimates is low, and more high quality randomised controlled trials are needed.

STUDY REGISTRATION

Clinicaltrials.gov (NCT02716870).

Teaching subjects with type 2 diabetes how to incorporate sugar choices into their daily meal plan promotes dietary compliance and does not deteriorate metabolic profile

OBJECTIVE

To determine whether teaching free-living subjects with type 2 diabetes how to incorporate added sugars or sweets into their daily meal plan results in a greater consumption of calories (fat or sugar) and deteriorates their glycemic or lipid profiles but improves their perceived quality of life.

RESEARCH DESIGN AND METHODS

In an 8-month randomized controlled trial, 48 free-living subjects with type 2 diabetes were taught either a conventional (C) meal plan (no concentrated sweets) or one permitting as much as 10% of total energy as added sugars or sweets (S). Mean individual nutrient intake was determined using the average of six 24-h telephone recalls per 4 months. Metabolic control and quality of life were evaluated every 2 months. Quality of life was assessed using the Medical Outcome Survey and the Diabetes Quality of Life questionnaire.

RESULTS

The S group did not consume more calories (fat or sugar) and in fact ate significantly less carbohydrate (-15 vs. 10 g) and less starch (-7 vs. 8 g) and had a tendency to eat fewer calories (-77 vs. 81 kcal) than the C group. Weight remained stable, and there was no evidence that consuming more sugar worsened metabolic profile or improved their perceived quality of life.

CONCLUSIONS

Giving individuals with type 2 diabetes the freedom to include sugar in their daily meal plan had no negative impact on dietary habits or metabolic control. Health professionals can be reassured and encouraged to teach the new "sugar guidelines," because doing so may result in a more conscientious carbohydrate consumption.

Large variations of sucrose in constant carbohydrate diets in type II diabetes

Several studies show that sucrose does not aggravate hyperglycemia in type II diabetes mellitus, but sucrose is still restricted in dietary recommendations. Since sucrose in high carbohydrate diets elevates fasting triglyceride levels, the effects of sucrose were evaluated in diets with fixed carbohydrate levels. Eighteen diabetic volunteers receiving no medication were given weight maintenance diets with 50 percent carbohydrate, 35 percent fat, 15 percent protein, and 120 g of sucrose for 10 days as inpatients. They were then randomly assigned diets of similar composition with either 220 g of sucrose (high sucrose diet) or less than 3 g of sucrose daily (complex carbohydrate [CHO] diet) for one additional month. There were no differences in fasting, one-, two-, and three-hour post-lunch serum glucose levels; 24-hour glycosuria; glycohemoglobin levels; fasting and postprandial serum triglyceride levels, or fasting high-density lipoprotein-cholesterol levels. Twelve patients with preexisting higher triglyceridemia had similar trends, but the postprandial triglyceride levels were lower in the high sucrose diet group of this subset (p less than 0.05 in the third week). Postprandial serum insulin levels declined in the second week on the complex CHO diet. More than 75-fold difference in sucrose intake with constant carbohydrate and fat did not affect glycemic or triglyceridemic control in type II diabetic patients. The reported high sucrose-carbohydrate-induced rise in fasting triglyceridemia was not present when a diet high in sucrose was given without changing total carbohydrate.

Dietary patterns and metabolic control in diabetic diets: a prospective study of 51 outpatient men on unmeasured and exchange diets

In a prospective, single blind study, 51 adult diabetic, male outpatients at or below ideal body weight (IBW), all but four of whom were insulin-treated, were randomly assigned to a calorically defined exchange diet (EXCH) or an unmeasured diet avoiding refined sugars (UNMEAS). Fasting chemistries, weights and 48-hr dietary recalls were obtained every 3 months for 3 years. There was no difference between groups in mean body weight, mean caloric intake, percentages of carbohydrate or fat intake, day to day consistency of caloric intake, or fasting chemistries. The patients whose actual weight tended to be less than IBW consumed more calories than their theoretical calculated needs (p = 0.002) without effect on glycemic control or stability of weight. Patients with low carbohydrate intake (less than 30%) had significantly higher triglyceride levels (p = 0.015). Otherwise, variations in dietary patterns were not reflected in fasting clinical chemistries. Individual fasting serum glucose levels were not related to consistency of carbohydrate intake, caloric distribution throughout the day or composition of diets. These results suggest that actual dietary patterns of subjects following exchange diabetic diets with precise caloric prescriptions are similar to those resulting from unmeasured diets with restriction of simple sugars. Other than correlation between carbohydrate intake and triglycerides, there was no detectable effect of variations in dietary patterns upon conventional chemical metabolic levels.