In Part 1, we covered what to add to your plate. This post is about how you eat, how to keep your blood sugar steady, and where intermittent fasting fits in.
How you eat matters
Digestion starts before the first bite. Seeing and smelling your food tells your brain it's time to get ready to digest. If you're answering emails or tidying the kitchen while you eat, you miss that step. Your nervous system is still in “go” mode, and your body is less prepared for the meal. Over time, poor digestion can lead to bloating, reflux and fatigue after meals. Research has also shown that eating quickly is linked to a higher risk of obesity.
Take five breaths
Put down your phone and take five slow breaths before you start. This helps shift your body into parasympathetic, or “rest and digest,” mode.
About 20 per bite
It sounds like a lot, but it quickly becomes a habit and helps with both digestion and fullness.
Don't flood the meal
Large amounts of water can worsen digestive discomfort in some people. Sips are fine, but try to drink most of your water between meals.
Relearning how to eat this way can take time. Digestive bitters or enzymes may help some people along the way. Low stomach acid, which becomes more common with age and with acid-reducing medications, can also play a role, and a trained provider can help address it.
Metabolic flexibility and blood sugar
Metabolic flexibility is your body's ability to switch easily between burning fat and burning carbs, depending on what's available. You burn fat between meals and while fasting, switch to glucose after a carb-rich meal, then go back to burning fat.
When that flexibility is lost, which is common with insulin resistance, inactivity or chronic stress, your body can't move glucose into cells efficiently. Blood sugar spikes higher and stays up longer. That's when you might notice afternoon fatigue, brain fog, trouble losing weight or sleep problems. In perimenopause, insulin resistance is also linked with more frequent hot flashes, and steadier blood sugar may help with energy and mood.
High blood sugar also drives the formation of advanced glycation end products, or AGEs, which form when sugar binds to proteins. They contribute to aging in the skin, blood vessels and organs, including the brain. Steadier blood sugar supports both how you feel day to day and how you age.
Three ways to steady your blood sugar
- Eat in order. Start with vegetables and fiber, then protein and fat, and eat your carbs last. In a study of people with type 2 diabetes, eating this way lowered the blood sugar rise after a meal by roughly a third, with significantly lower insulin.
- Move after meals. A 10-minute walk after eating can noticeably lower the blood sugar rise, especially after your largest meal.
- Learn your own responses. Wearing a continuous glucose monitor (CGM) for two weeks shows how your body reacts to specific foods, and it's different for all of us. What spikes my blood sugar may not spike yours.
Repeating a CGM now and then is useful because things change. In perimenopause, for example, falling estrogen reduces insulin sensitivity, so blood sugar control can get harder. Some people wear one more often as a way to track and reinforce their nutrition and lifestyle choices.
Changes in blood sugar regulation can show up in your labs more than a decade before a diabetes diagnosis.
Intermittent fasting: a tool, not a rule
Fasting can help in certain situations. It can improve insulin sensitivity and help line up your eating with your body clock, though in many studies the benefits have been largely attributed to eating less overall. It can also be a simple way to cut back on late-night grazing.
A longer overnight break also gives the migrating motor complex, your gut's “housekeeping” wave that clears the small intestine between meals, more time to do its job. Research suggests an earlier eating window works better than a later one.
Be careful if you're in perimenopause. Research is limited, and aggressive fasting may disrupt sleep, lower thyroid hormone levels and make it harder to maintain muscle. The same goes for athletes in heavy training, older adults concerned about muscle loss, and anyone managing a chronic illness.
Fasting isn't recommended during pregnancy or breastfeeding, or for anyone with a history of disordered eating. If you take medication for diabetes, talk with your clinician before trying it, since fasting can cause low blood sugar.
A 12-hour overnight fast, for example from 7 p.m. to 7 a.m., is a reasonable starting point for most people.
Where to start
Try one of these for two weeks: five slow breaths before each meal, eating your vegetables first at dinner, or a 10-minute walk after your biggest meal. If you're unsure which pillar to focus on, the Longevity 101 check-in may help you choose.
References
- Ohkuma T, et al. Association between eating rate and obesity: a systematic review and meta-analysis. International Journal of Obesity. 2015.
- Goodpaster BH, Sparks LM. Metabolic flexibility in health and disease. Cell Metabolism. 2017.
- Thurston RC, et al. Vasomotor symptoms and insulin resistance in the Study of Women's Health Across the Nation. Journal of Clinical Endocrinology & Metabolism. 2012.
- Shukla AP, et al. Food order has a significant impact on postprandial glucose and insulin levels. Diabetes Care. 2015.
- Reynolds AN, et al. Advice to walk after meals is more effective for lowering postprandial glycaemia in type 2 diabetes mellitus than advice that does not specify timing: a randomised crossover study. Diabetologia. 2016.
- Zeevi D, et al. Personalized nutrition by prediction of glycemic responses. Cell. 2015.
- Tabák AG, et al. Trajectories of glycaemia, insulin sensitivity, and insulin secretion before diagnosis of type 2 diabetes: an analysis from the Whitehall II study. Lancet. 2009.
- Uribarri J, et al. Advanced glycation end products in foods and a practical guide to their reduction in the diet. Journal of the American Dietetic Association. 2010.
- Deloose E, et al. The migrating motor complex: control mechanisms and its role in health and disease. Nature Reviews Gastroenterology & Hepatology. 2012.
- de Cabo R, Mattson MP. Effects of intermittent fasting on health, aging, and disease. New England Journal of Medicine. 2019.
- Sutton EF, et al. Early time-restricted feeding improves insulin sensitivity, blood pressure, and oxidative stress even without weight loss in men with prediabetes. Cell Metabolism. 2018.
- Lowe DA, et al. Effects of time-restricted eating on weight loss and other metabolic parameters in women and men with overweight and obesity: the TREAT randomized clinical trial. JAMA Internal Medicine. 2020.
This article is for general education and isn't a substitute for personal medical advice. Please talk with your own clinician before changing your medications, supplements, diet or exercise routine.