It’s no news that a high protein breakfast will keep you satiated for longer time periods than a sugary cereal. There’s also existing evidence that whey proteins are an excellent choice for people with type II diabetes as their effects on GIP, GLP1, and insulin help reduce postprandial glucose levels in T2DM. Against that background. it is quite surprising that no previous study did what researchers from the Tel Aviv University, the Central University, Caracas, the Lund University, the Weizmann Institute of Science, and the Hebrew University of Jerusalem did, recently, i.e. “examine whether a high-energy, protein breakfast containing whey leads to a greater weight loss and reduction of overall postprandial glycemia and HbA1C compared to isocaloric diet with a different source of protein or carbohydrates at breakfast for 12 weeks in type 2 diabetes subjects” (Jakubowicz 2017).
The scientists based their assumption that whey would be particularly effective in improving glycemia and the long-term glucose gauge HbA1x on several acute studies that have shown that whey protein exerts a greater postprandial glucose-lowering effect compared with other protein sources, such as soy, fish, gluten, eggs, casein, in healthy (Gunnerud 2012; Hall 2003; Nilsson 2004 & 2007; Bowen 2006) and type 2 diabetes individuals (Jakubowicz 2014; Bowen 2006).
Figure 1: Overview of the most important results of the study (Jakubowicz 2017).
For their study, the international team of scientists recruited fifty-six type 2 diabetes participants aged 58.9±4.5 yr., BMI 32.1±0.9 kg/m² and HbA1C 7.8±0.1% (61.6±0.79 mmol/mol) who were randomized to one of 3 isocaloric diets with similar lunch and dinner, but different breakfast:
- high whey protein breakfast (WBdiet | n=19, 8 males, 11 females) contained at breakfast 25% fat, 50% carbohydrates and 25% (42 g) protein of which 28 g are whey concentrate (80%);
- high mixed protein breakfast (PBdiet | n=19, 9 males, 10 females) contained at breakfast 25% fat, 50% carbohydrates, and 25% (42 g) protein mainly from eggs (7 g), tuna (20 g), soy (7 g);
- carbohydrate breakfast (CBdiet | n=18, 9 males, 9 females) contained at breakfast 25% fat, 64% carbohydrates and 11% (17 g) soy protein
As previously hinted at, the three diet interventions had the same meal-timing schedule and energy distribution consisting of high-energy and protein breakfast (660±25 kcal), medium-sized lunch (560±20 kcal) and low-energy dinner (280±15 kcal).
“The composition of lunch in the 3 diets was 29% fat, 48% carbohydrates and 23% protein. The composition of dinner in the 3 diets was 38% fat, 31% carbohydrates and 31% protein. The protein source for lunch and dinner was chicken, meat, fish or turkey. Lunch and dinner did not include dairy foods. The diet plan was calculated for a daily caloric intake of 1500 kcal. However, the daily caloric intake for each participant was obtained by subtracting 500 kcal from the calculated Harris Benedict Equation, in order to achieve progressive weight loss” (Jakubowicz 2017)
The subjects’ body weight and HbA1C were examined after 12 weeks. Furthermore, all participants underwent 3 all-day meal challenges for postprandial glycemia, insulin, C-peptide, intact glucagon-like peptide 1 (iGLP-1), ghrelin and hunger and satiety scores.
Figure 2: The beneficial effects on glucose (A) were probably mediated by a significant increase in insulin (B), GLP1 (C) and C-peptide (D) levels, which are all usually too low in type II diabetics (Jakubowicz 2017).
What the scientists found was that there was an overall postprandial AUCglucose in all both high protein groups, albeit with the greatest reduction in of 19% in the WBdiet, and “only” 15% in the PBdiet compared with the high carb breakfast condition in the CBdiet group (P<.0001).
The HbA1c reduction was significant and practically relevant: In fact, the reduction of 0.9% (11.5 mmol/mol) HbA1C achieved with the WBdiet is comparable to the decrease expected with glucose-lowering medications, such as dipeptidyl peptidase 4 (DPP4) inhibitors, sodium-glucose co-transporter 2 (SGLT2) inhibitors, meglitinides and thiazolidinediones (Nathan 2009).
Figure 3: The Increased satiety and decreased hunger with protein and whey will also help T2DM patients stick to their diets – and you know: the best diet is the one you can adhere to (Jakubowicz 2017).
Against that background it is not surprising that, compared with PBdiet and CBdiet, WBdiet led to a greater postprandial overall AUC for insulin, C-peptide, iGLP-1 and satiety scores, while postprandial overall AUC for ghrelin and hunger scores were reduced (P<.0001).
Also, since all diets were 500kcal below the subjects’ energy requirements, it’s likewise not surprising that after 12 weeks, HbA1C was reduced in all groups — with WBdiet (0.89±0.05%) > PBdiet (0.6±0.04%) > CBdiet (0.36±0.04%).
A result that is, by the way, reflected in terms of weight loss, as well with the “the participants on WBdiet lost 7.6±0.3 kg, PBdiet 6.1±0.3 kg and CBdiet 3.5±0.3 kg (P<.0001)” (Jacubowicz 2017).
Bottom line: “Whey protein-based breakfast is an important adjuvant in the management of type 2 diabetes” (Jakubowicz 2017), the authors write and they’re correct. What one should not forget, though, is that one of the main messages of the study at hand is that the good old adage of “having breakfast like a king and dinner like a pauper” is spot on. As Jakubowicz, et al. point out, “[t]his dietary adjustment may have a therapeutic advantage for the achievement of optimal metabolic control and may have the potential for being preventive for cardiovascular and other complications of type 2 diabetes” – with whey being a useful, but not a necessary addition to the high protein high-calorie breakfast (and reduced intake at dinner).
As the authors point out, their study does, however, suffer from the lack of a healthy control group. “Thus [the scientists] cannot determine whether these effects occur also in healthy people” in whom the increase in insulin release with whey protein could potentially entail different long-term effects – let’s hope that this issue is resolved in future studies | Comment on Facebook!
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