Tag: Exercise for weight loss

How Much Exercise Do You Need to Lose Weight?

On By Dr. Scott RennieIn Weight Loss & Metabolic HealthLeave a comment

Patients ask me all the time how much exercise really matters for weight loss. The honest answer is that it depends on what they are trying to do. Losing weight quickly, keeping it off, and staying healthy are three different goals, and exercise performs very differently against each one.

On one point the research is not ambiguous. Exercise on its own rarely produces large weight loss. Most trials show modest changes, roughly half a kilogram to three kilograms, and that is in people putting in 180 to 270 minutes a week (Jakicic et al., 2019). Below 150 minutes, most people do not lose much at all. I see the same thing on my schedule. Patients who start walking three times a week often feel noticeably better while the scale barely moves, and that gap is worth naming out loud before they get discouraged by it.

None of which makes exercise optional. It is among the best tools we have for preventing regain. Long-term data show that people sustaining higher volumes, often north of 250 minutes a week, are considerably more likely to hold onto a 10 percent loss (Jakicic et al., 2014). That is where the real return sits.

Paired with dietary change, the numbers improve. Adding exercise to calorie restriction increases short-term loss by about 20 to 25 percent over diet alone (Wing et al., 1998; Goodpaster et al., 2010). I had a patient who was cutting calories carefully and getting almost nothing for it until she added regular cycling. With both together she lost roughly twice as much and held it considerably longer.

Type and volume both matter. For general health, 150 minutes of moderate activity a week is the baseline. For meaningful weight loss, 250 to 300 minutes is closer to what is needed. For maintenance, somewhere in the 200 to 300 range seems to work. None of this requires a gym. Walking, yard work, and even light activity like standing or slow walking accumulate, and a 2021 doctoral dissertation found that increasing light-intensity activity independently predicted weight loss at both 6 and 12 months (Jackson, 2021).

Practically, I tell patients to start from where they actually are. Adding steps, breaking up long stretches of sitting, and picking something they do not dread produces more consistency than any prescribed routine they will abandon in a month. Thirty to sixty minutes on most days works whether it comes in one block or four. And if weight loss is the goal, it has to be paired with dietary change; exercise alone will disappoint them.

Exercise is not a shortcut to weight loss, and patients who come in expecting it to be will be let down. What it does do is keep lost weight off, improve metabolic health, and protect function as people age. Move more, sit less, keep going.

Scott Rennie, D.O.

References

Jakicic JM et al. Physical Activity and the Prevention of Weight Gain in Adults: A Systematic Review. Med Sci Sports Exerc. 2019;51(6):1262-1269.

Jakicic JM et al. Obesity. 2014;22:2284-2292.

Goodpaster BH et al. JAMA. 2010;304(16):1795-1802.

Wing RR et al. Am J Clin Nutr. 1998;67(3):551-558.

Physical Activity Guidelines Advisory Committee. 2018 Scientific Report.

Jackson R. Doctoral dissertation, 2021.

Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

Why Exercise Matters for Obesity Beyond Weight Loss

On By Dr. Scott RennieIn Weight Loss & Metabolic HealthLeave a comment

When we counsel patients about obesity management, one of the most common misconceptions is that exercise by itself is the best way to lose weight. On video visits, patients often tell me they’ve started walking every day or signed up for the gym, expecting big changes in their weight within weeks. Sometimes even clinicians lean into that belief. But the data consistently show that diet has a much stronger impact on weight loss than exercise alone.

That doesn’t mean physical activity isn’t important. Far from it. The average weight loss from exercise alone is modest, usually around two to three kilograms. Add diet changes, and outcomes improve significantly. Patients who combine both tend to lose more weight and, more importantly, keep it off better.

The role of exercise extends well beyond weight loss itself. It preserves lean body mass, lowers blood pressure, improves cholesterol, and supports long-term physical function. Pharmacotherapy shows the same pattern: medications can drive the weight loss, but adding structured activity makes the results more sustainable.

The type of activity matters. Aerobic exercise, walking, cycling, swimming, drives calorie expenditure, but resistance training helps maintain or build muscle, which matters most when calories are reduced. The combination works best. Most recommendations center around 150 minutes of moderate-intensity activity per week, which can mean brisk walking 30 minutes a day, five days a week. Some patients prefer high-intensity interval training because it takes less time, though not everyone tolerates it well. For beginners, discomfort and injury risk run higher, so starting gradually makes sense.

It’s important to manage expectations. When a patient logs on discouraged because an exercise program hasn’t led to major weight loss, that’s a teaching moment. Diet has to be part of the plan too, and exercise alone was never going to get there. Once patients understand that, they’re more willing to combine strategies instead of giving up.

Adherence and enjoyment are often the deciding factors. People stay consistent when they choose activities they actually like. One patient may thrive on group classes, another prefers solitary walks with a podcast. Both approaches work, if they’re done regularly.

Daily habits outside the gym matter too. Non-exercise activity thermogenesis, or NEAT, is the energy used in everyday movement: standing during phone calls, walking instead of driving short distances, taking the stairs instead of the elevator, plus gardening, housework, walking a dog, small things patients can relate to. Increasing NEAT can meaningfully raise daily calorie burn without feeling like a formal workout.

For us as providers, diet drives most of the weight loss, but physical activity is essential for maintaining it and for overall health. Framing it this way helps patients set realistic expectations while reinforcing that movement stays a regular part of life.

Reference:

Swift DL, McGee JE, Earnest CP, Carlisle E, Nygard M, Johannsen NM. The Effects of Exercise and Physical Activity on Weight Loss and Maintenance. Prog Cardiovasc Dis. 2018;61(2):206-213. https://pubmed.ncbi.nlm.nih.gov/30003901/

Scott Rennie, D.O.

Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.